Gave up making Christmas puddings and cake years ago. No one ate the cake and we bought a marvellous Christmas pudding one year at an artisan food fair, which I can't better, so we buy one every year now.
I also prep all my Christmas Day food in advance using Delia's Christmas Cookbook. Carrot and swede mash in foil containers in the freezer, as well as red cabbage and parmesan parsnips. Pigs in blankets likewise and roast potatoes par boiled and oiled on a tray in the fridge the day before.
The aforementioned Christmas pudding fits in the slow cooker and warms up nicely during the morning out in the utility room. The the only thing I cook on the day is the turkey and the sprouts.
I gave up trying new ideas for the dinner years ago and stick to the same formula every year. When I worked full time I took annual leave for a week toward the end of November/begining December as my Christmas 'prep' week. My colleagues thought it was hilarious, but it meant I could enjoy the day without slaving over the cooker, but also knowing it was mostly home cooked!