If you are restricted on nuts, it might be better to make your own mince, but some are ok to buy. If you buy them now, add some grated apple, extra lemon and orange zest and some liquor (brandy, gran marnier) and allow to steep together for maybe 2-3 weeks. Then make up the pies and freeze.
I also freeze logs of cookie dough. I make plain, lemon and orange, chocolate chip and occasionally coconut versions. Just wrap in cling film as a log and freeze, can slice and bake from frozen as needed. Very handy to make on Christmas Eve for Santa, but if you have lots of kids coming who may want something plainer come desert time or later in the afternoon, that may be nice.
You can prep your veg, blanch and freeze in advance. Or prep and leave in water the night before. I tend to do the latter but I only have small groups. If you may have help on Christmas Eve, that could be an option, or else do a batch a week of different things to freeze in advance.
Would everyone accept , a trifle with no nuts on top as dessert? Does it need to be elaborate? And also, do you need to make it? Will any guests be asking if there's anything they can bring? Cheese course, dessert, starter, some sausage rolls or nibbles for evening are all useful things to have in your mind. Or indeed the stuffing, a bowl of mashed potatoes, a veg dish they know their kids will eat....
You could do turkey stock now for gravy, ask butcher for turkey bones and the stock will freeze great. Or look for turkey stock in better supermarkets.
When it's quiet now, sit wih a cup of tea, pen and paper, and start thinking. Guests will walk in the door, and....be given a drink? Need breakfast? Staying night before? Arriving just before lunch?
Work through the day, writing down things you wil need to do each part. Drinks and nibbles, starter?, Turkey, veggies (what types would you like?), spuds (roast, mashed, done a different way?), gravy, bread sauce, salt and pepper, ketchup, stuffing, drinks, ....cheese, crackers, grapes, desert, cream, custard, pudding, cake, ...tea, coffee, milk, sugar, chocolates...
You mightn't want all of those, but list everything YOU will likely need or your guests may ask for (hence ketchup for kids, may not be needed in your family).
Do you want candles, crackers, nameplates etc on table? Do you have a suitable cloth, and napkins? Enough crockery, cutlery and glasses? A few nice hand towels for bathrooms, and tea towels for kitchen, and plenty of useful tea towel for kitchen (see willing helpers comment below)? A couple of aprons in case anyone offers to help and you are willing to let them in cooking?
Do you want to buy in ice rather than making loads? (Can also be useful to keep things cold outside a fridge if needed).
Is there anything that great auntie Genevieve will sulk if she doesn't get (eg cranberry sauce)?
Yes, don't forget cleaning stuff. Washup liquid, dishwasher tablets, bin bags, spare rubber gloves (for willing helpers as you relax afterwards!), kitchen towels even if you don't normally use them, toilet rolls, handsoap, bathroom cleaning spray, etc.
Enjoy!