Well, if it was me cooking for 13, I would do the turkey the day before, slice, and put in a casserole dish with some gravy to reheat on the day. Frees up your oven for sausages, bacon, stuffing, roast potatoes and parsnips etc. You can freeze extra gravy in advance too.
I make my stuffing from scratch well in advance and freeze it, some in an ovenproof dish to go in the oven, and some in a freezer bag for inside the bird.
Think of veggies that can be cooked in the microwave for speed, and save your hob.
We usually have Carrot and Parsnip puree which can be made ahead. This is for 12 servings.
1.45 kg carrots peeled and chopped
700 g parsnips peeled and chopped
30 ml lemon juice
6 tablespoons creme fraiche
freshly grated nutmeg
25 g melted butter to serve
Boil carrots with lemon juice, in salted water and in another pan boil parsnips with salt but no lemon. (If you have a really big pan it's fine to cook them altogether.)
When tender, drain, and allow to dry off slightly. You can now either mash with a potato masher or use a stick blender in the pan, adding the creme fraiche. Continue until you have a smooth puree. You can also use a food processor and do it in batches, but this is very messy and makes more washing up! Grate nutmeg and stir in to taste.
Put into an ovenproof dish and cover. You can reheat in a low oven until piping hot, stirring occasionally, drizzle with melted butter to serve. Or, I reckon you could reheat in a microwave, stirring through at intervals. You could also start to warm it in the microwave and transfer to the oven if you have room.
I actually make a small amount and freeze in a microwaveable dish, I think you could freeze it in small 4 portion amounts in advance and thaw it out successfully before you need to reheat it. (If you freeze it as a big amount it will take ages to thaw.)
This is really tasty with roast beef as well. If you want to feed it to babies, you can just leave out the salt, reserve the baby portion and add salt to the rest after reheating as you stir it.
Have a trial run before Christmas, with enough for 4, say, to see if you like it and if you will have big enough pans for 8 more portions!