I would prep all the buffet food for the next two days
Cold meats, bread like items, hard boiled eggs, cheese board, Christmas pudding, trifle, grapes, satsumas, pickled onions (this is all dependant on what your pregnant body can face/not face).
Make sure to have fancy pregnant drinks in, fizzy grape juice, jersey milk, decaf/herbal teas.
Probably clear rest of kitchen.
Then have a bath with new/luxury bought in advance bubbles. Get some escapism reading material whatever you feel like reading, Christmas good housekeeping magazine, feel good novel, biography of someone you admire. Bathe, body face creams be all soft and silky.
I would watch something easy like Bridget Jones, Harry Potter, Barbie.
Eat what I fancied (with pregnancy guidelines).
An get H to give me a foot massage on his return whilst still hogging remote although I might have moved on to gentle whodunnits by evening.
All whilst the pretty Christmas tree lights twinkled in the corner.
Actually I might watch the Christmas BBC lectures, if H was interested that would be the evening viewing.
I would save the walking until 27th.
I am assuming you would have slipper socks, blankets, I might bring more pillows down. I might even look at the pictures in a coffee table book.