While I think there is definitely prep that can be done in advance, I also think that a stress free traditional Christmas dinner is a bit of a myth tbh
It maybe helps to be realistic about it from the off?
We have a bit of a tradition in my family that everyone contributes something towards Christmas dinner. Red cabbage is my speciality, dm always makes the Christmas pudding, db orders the cheese etc so all the burden of work doesn't fall to one person.
We tend to not have a formal starter these days - the kitchen is busy enough as it is. Instead we have a glass of fizz and posh nibbles just before the final onslaught of cooking. Ask someone else to bring both
(or buy from M&S?)
For the main course, I think the main thing is to try not to go totally overboard with side dishes. I know people who do 3 types of potato and 7 different veg which feels like overkill to me. I also keep some of the veg pretty plain - usually steamed carrots and sprouts - as I think it's a nice contrast to the
You can make stuffing ahead of time and freeze I think? I don't do balls, I stuff the bird with some and maybe cook the rest in a little dish if there's some leftover. Red cabbage is a very nice side dish which can definitely be cooked ahead and frozen. YY to cook ahead gravy. I've also heard that you can parboil and then freeze potatoes in advance too - maybe one to test out beforehand?
For the veggies I'd maybe do a mushroom and cheese tartlet? Ready rolled bought puff pastry circles topped with sauteed garlicky mushrooms, fresh thyme, cheese of your choice.
We always have Christmas pudding and luckily everyone likes it which again keeps things simple. If you do want to do a choice of dessert, again can you ask someone else to bring and serve it?
And definitely delegate on the clearing up 