I agree with others.
Make a plan of your menu - what things of DGran's dinner do you really want, and what things would you like to do differently?
Once you have your menu, that gives you the basis of starting loads of lists.
Who can do what dish/course?
Table settings and other crockery needs
Shopping lists - of all the ingredients, and also anything that you want to buy in pre-prepared!!
Timetable for the day
Jobs/elements of the meal for delegation to others
YYY to others doing different elements.
Ask people to bring their specialities if they have any - so anyone great at mince pies or cookies, or baked ham (preferably cold and sliced), or green beans in cream and bacon, or whatever?
There can be drinks (alcoholic and non-alcoholic), snacks to nibble beforehand or chocolates or other nibbles for afterwards, cold starters (already plated up is fantastic but at least prepped to serve easily is great) to bring to serve as they are.
Veggies prepped for the oven (either to just reheat like cauli cheese or green beans w/cream and bacon, or to tip into a dish and bake - roasted root veg can be prepped and have their seasonings added and come in a plastic tub/Ziploc bags/on a roasting tray (the latter only if you know it will fit into the oven) as examples).
Stuffing, in an oven-ready dish or a plastic tub of ready-rolled balls to put on a baking tray, would also travel well.
On desserts: plum pudding or another dessert (having at least 2 desserts might be a good idea for that many - trifle, fruit salad, chocolate mousse or jelly would all travel well and need no cooking, or bread and butter pudding or something like that to cook while you are eating main course? Or icecream or sorbet if you have freezer space - especially if someone brings those and you have taken out other items you have prepped in advance). Or even a large plastic tub of whipped cream to serve with dessert.
Table settings - you will need cutlery and dinner plates for all, but do you need soup bowls, side or starters plates, dessert bowls or plates, cheese plates, wine glasses (and just 1 each or red and white versions), water glasses etc. Do you have enough of all these? Can you borrow some (from attendees) or buy additional or rent them? Would people eat off (good) paper or plastic plates?
Other table needs:
Serving dishes for each element. (And for that many people, I would do at least 2 and possibly 3 smaller dishes of each thing rather than 1 big one - if you have the space). You may want to serve most things on the plates - or just the meat and let everyone serve themselves at the table. But even if you plate up in the kitchen, you will probably want some serving dishes to allow people serve themselves seconds.
Might you want 1/2 platters or large plates (even spare dinner plates) for seconds of meat?
And serving spoons or other implements for each dish.
Gravy jugs (as above - have a few - but regular jugs can be used as gravy or sauce jugs if necessary).
Any other sauces needing jugs or bowls? (Cranberry, mustard, bread, ketchup) - different families have different things that "must" appear for Christmas.
Baskets for bread, toast or crackers? Plates/boards for cheese?
Dish for chocolates or plate for mince pies or biscuits?
Do you need bread/toast and butter for starters (soup or pate I'm mainly thinking)? Butter could go on saucers if you don't have butter dishes.
Salt and pepper - again try and have a few scattered down the table.
Milk and sugar for tea and coffee at the end of the meal - and do you have enough cups and saucers, or mugs?
Water jugs?
A big enough table, or tables linked together, and chairs. And perhaps a side table to hold things like serving dishes for seconds or spare bottles of wine/jugs of water if the table would be cluttered.
Tablecloths and/or napkins? Candles? Crackers? Other decorative elements?
Heat protection for the table - placemats, or a blanket under the tablecloth if you don't have a heatproof mat? Or your table may not need that.
Do you want any trays to serve things to the table or for tea/coffee or other things later in another room?
And also cooking implements - roasting and baking trays, large (and smaller for sauces) pots, serving spoons, whisks, wooden spoons, carving and other knives, ladle(s), mixing bowls, chopping boards....work through your menu and think about what you need for each element.
(and think about how much washing up you want to do, or what you can borrow from others coming - either to borrow ahead of time and return on the day, or borrow on the day and return later in the day or in the next few days).
You probably want extra kitchen towels, cling film and tin foil, and things like washup liquid and bin bags on your shopping list.
You may want extra teatowels available easily for willing helpers, or an extra apron, and some extra oven gloves (for helping in the kitchen and serving).
But it can be handy to have the tinfoil dishes for cooking in - especially rectangle ones that can fit side by side in the oven (in fact, it could be handy to cook smaller amounts of certain sides initially, and a second batch goes in as the first lot are cooked and you are serving - so you have spare roast potatoes or other favourites for when people want seconds - to reduce pressure on the oven space).
Make sure you have enough roast potatoes for 1 each (2 if you have space in the oven) but then make either plain mash or a festive mash (add some herbs and use butter and cream for the mashing perhaps) to supplement.
Don't do tonnes of different sides - 1 veg might not be enough but think about how you would prepare them and oven/hob space etc.
So maybe 1 needing oven space (roasted root veg are lovely, can be prepped the day before and reasonably quick to cook once the turkey is out, or butternut squash) and 1 or 2 on the hob (glazed carrots with onion, frozen peas, brussels sprouts etc?). A cauliflower cheese can be good too - chop it into even sized florets when prepping, steam it, pour over the cheese sauce (which can be made the day before), add a handful of grated cheese and pop under the grill to brown up if oven space is not available.
I would try and have the gravy made, or at least the stock if you are making giblet/turkey bits stock, the day before. Then add in the juices from the turkey and reheat in a pot on the stove rather than worrying about making it and thickening it up in the roasting dish. A good glug of wine, bisto, turkey stock, (carrot cooking water is good too if more liquid is needed) and the turkey juices make really good gravy.
For that many people, stuffing balls might be handy but a faff to make (although that could be a handy one to give to another guest as their contribution!) - but do the stuffing in a large separate dish rather than in the turkey. Like roast potatoes and roast veggies, it can also go into the oven once the meat comes out. (Put the meat on a carving dish or large platter, cover with a double layer of tin foil and then put a bath towel folded in 2 over the top to keep it warm and let it rest for an hour - to finish cooking and let all the juices seep into the meat - it will stay hot if you insulate it like that).
Do as much prep in advance:
On 24th:
Peel potatoes and soak them in water ready to roast. Some people even par-boil them and roll them in the goose fat (or even polenta) and lay them on roasting tins the day before, but I have never tried that (others have prepped them and frozen up to a month ahead, but I've never tried that either).
Peel and chop the veggies. Carrots and sprouts and cauliflower can soak in water overnight, but parsnips need to be in an airtight tub with no water or they go slimey. I tend to peel onions and garlic the day before, but not chop them until I need them (except for any going into mixed root veg that I am marinading ahead of time with olive oil, salt and pepper and maybe some other seasoning/juice from a satsuma/balsamic vinegar).
Make the giblet stock, or even the gravy.
Breadcrumbs can be made anytime and frozen. Or you can make up the stuffing ahead of time and freeze too - either as a pyrex dish to put into the oven (thaw it first though, not straight from freezer to oven!), or as balls to cook on a baking sheet. If you don't make the stuffing and freeze it, do try and make that on 24th (but don't faff with balls at that stage).
I also often have stock frozen from roast chickens (I boil the carcass with the clean!! peelings of the carrots and onion from that dinner, and adding my herbs and water) which can go in the gravy. Or you could ask your local butcher (especially if you already know them) if they might have turkey carcasses in late November as some people want Thanksgiving turkey crowns (4th Thursday in Nov is thanksgiving, so 23rd this year) and make and freeze some turkey stock then.
Soup and mince pies can also be frozen ahead of time, and lots of other things too. And I tend to try and make a plastic box full of ice ahead of hosting events too - just remembering to make the trays of ice and empty them out every couple of days into the tube in advance. (I also tend to freeze extra slices of lemon and lime from drinks as we never use a whole one at once normally, and they are great to use another time instead in drinks and jugs of water - but I will do a batch in advance of hosting an event too).
Have some nibbles thought about to keep people from invading the kitchen when you are mad busy - crisps and dips, bowls of nuts, savoury crackers and cheese/pate/cured meats, olives, etc. Not necessarily hot nibbles as you will probably need the oven. And try to have the main drinks dispensing area in a different room so a bowl of ice, your slices of fruit and all the glasses and drinks are put there ahead of time.
And other than asking guests to bring elements of the meal, think about what jobs you can ask them to do.
Are you happy having people in the kitchen with you and working alongside you, or just keeping you company?
Can you get someone to keep on top of the washing up before the meal, as pots and cooking implements get finished with and serving dishes filled? And other things like emptying the bin as it gets full (especially if you are using disposable dishes), or keeping kettles boiled for hot water as needed etc.
Would you prefer to set the table in advance, or ask someone to do that on the day to keep them busy?
Someone on serving drinks, someone else on making sure nibbles are ok, someone else on playing with DCs or keeping elderly DGPs entertained....etc.
Plates can be heated by putting them into the oven once you have turned it off, by running them through a quick cycle in the dishwasher shortly before eating (and only opening the door when you are ready to serve), or by soaking in clean hot water in the sink and then quickly dried (by a helper) as you are ready to serve.
ALL washing up after the meal is delegated to others!