Do everything you wouldn't have time for if you had a house full., As others have suggested, have your day planned, read in bed with a coffee, a lazy bath, and enjoy your pets.
Eat what you want not what everyone else wants which I usually do at Christmas if we manage a family one. My DD lived abroad for years so it was a quick Facetime which DH hated.
Find some films that will not make you sad DH usually has Norman Wisdom who makes me cringe but I keep quiet.
My other DD has never joined in as it is too far to come if the weather is bad and snow gates shut on their route.
We will not be having turkey or Goose as there will be too much left over so it will be Duck and Gammon.
Could a steam be started on Gransnet for all those on their own this Christmas? To let you know you are not forgotten, everyone else is too tied up in cooking feeling frazzled and in some cases just wishing the guest would disappear so they can have a good old snooze.
We all whitter on about Christmas and forget that a lot of people are on their own or visiting loved ones in the hospital putting on a brave face, which I have had to do, ICU is no place for tinsel and merriment and some will be visiting there.
I hope you get a really special treat day planned for yourself.