Boxing Day:
make a pie with leftovers - turkey, sausage, stuffing, chopped up veg, bread sauce etc (i leave out red cabbage and cranberry sauce). Mix in a white sauce (you could buy jars ready made to save you making it) and top with shop bought puff pastry sheets
Alternatively if you don't have any leftovers but turkey, make coronation turkey to go with baked potatoes.
I know already mentioned but will repeat - milk is something we always went through, so many cuppas, cereal, sauces.
Have some storecupboard meals in mind eg tuna & sweetcorn pasta bake.
Definitely have at least one takeaway and meal out.
As you have fridge space, cheese, pate, pork pies, chutney make for an easy but lovely lunch/tea. Buy a load part baked baguettes. I can recommend Tesco multigrain with sourdough, and obviously crackers.
Crumpets and tea cakes can be used for breakfast or if anyone needs something between meals.
If it were me, I'd welcome the escape to a supermarket to top up after Christmas and sit and have a quiet cuppa in the supermarket cafe!