After we got married and started to learn to stand up for ourselves (after our requests to only eat in 1 house even though we'd visit both when down were completely ignored - there's only so many years you can do 2 full turkey dinners), we had a couple of years where we stayed at home just us 2 before DD arrived. And we still have many years when we stay at home just us 3 (which is not that different TBH except for needing a stocking).
We had always done a tree etc even if we were travelling.
We've always done a nice meal on Christmas Day - not always roast turkey, but usually some kind of roast. We do a lot of prep on 24th afternoon - peeling veg and potatoes, making stuffing etc.
On Christmas Day, we eat dinner in the late afternoon/early evening (5-6pm start usually). We throw the turkey in when we get home from mass and extended family calls (sometimes we've had it in on the timer ahead of time, sometimes we've come home between calls to get it started, now we only have 1 call so do it on return).
Doing spuds and veg and gravy etc are very relaxed, with someone (or everyone) popping into the kitchen every half hour or so to baste turkey and do the next step. In between drinking wine in front of the fire and opening presents.
While it might be Christmas party hits (classic cheese!) or else the radio played earlier in the day, we tend to have lower lamplight and candles (rather than overhead lights) as the backdrop to a gentler cadence of Christmas carols and classical music later in the afternoon. And often the tv goes on once the presents have been opened (DD wants to watch something while we finish dinner and make the family phonecalls).
After Christmas we normally have a lot of visits to do (involving travel), and December is normally frantic both at work and shuttling DD to events and organising events ourselves in voluntary roles, as well as the social whirl. So taking time to slow down for a day (2 if we are really lucky) is well deserved.
I keep saying I will take time to do a couple of nice hikes in the mountains near us, and to just read for a day beside the fire, and to watch a few movies in peace.....and none of those ever happen. But depending on how things are in the world and locally this year, maybe it just might be my chance to slow down properly this year. I'm also keeping my little camping stove (Kelly kettle) at home rather than putting it into storage, and thinking about a small log burner for the garden, to wrap up in my woollies and sit out there with DH and some wine some evenings.