So sorry, and of course I understand what you are saying. Christmas is a tough time for anyone alone who remembers those who made such a time so memorable.
This is why I am not happy with all the hype at Christmas, it makes it so hard for those who are grieving and alone or cannot afford to celebrate this occasion.
You need to keep occupied on the day and preferably the day before and after, if the weather is ok and you are mobile try going for walks, and if you are aware of any older neighbours on their own, perhaps knock on the door and see if they are ok, they might be in need of a chat or not but is worth a go. Read books, eat well, and as has been said raise a glass to absent loved ones.
I also believe there is a thread on here on Christmas Day if I’m not wrong, I have heard it mentioned, for those on their own.