I certainly don't over-think it, I'm more 'Bah humbug)
I don't do a tree or decorations, I buy cards and gifts for 3 people, i spend 'the holiday' on my own and don't speak to anyone.
I shut the door on 23 or 24 Dec, and refuse to open it again until at least 27th.
I try my hardest to sleep through a much of those few days as I possibly can, so double-dosing meds and painkillers is my annual ritual on 24th.
There are pizzas, pies, allsorts, in the freezer, there's always a pot of stew on the go throughout the winter, so I just decide what I fancy, about 30mins before I want to eat.
I generally don't even watch tv because I don't want anything to do with the outside world for at least 3 days.
New year is just as bad, so I'll hibernate fit another couple of days ago I don't have to see/ hear anything about that too.
I'll eventually venture out again on about 3 or 4 jan