Perhaps you can take a look from another angle. Just think if someone said to you, You are free to do what you want, so you choose. Years ago my sister was in a very stressful job and had little time to herself. She was invited to various peoples for the chrismas day, but so as not to upset them she just said that she was already invited elsewhere, so there was no problem. She actually got in food that she liked and was not much effort to make, stayed in her dressing gown all day, only got up when she was ready, and was very happy just having a rest, pleasing herself and did the same on boxing day. She then returned to work in a much better state, rested and not having spent a fortune , nor eaten a lot too much. It meant she went back to work feeling much better and brighter, and hearing the moans and groans from the others about expense and arguments etc felt she had had a much better day. So that is one thing you could do. Think just what you really like, whether it is fish and chips and icecream for dinner , and dont even wash up but just have a total days holiday from any work. Have a long lazy bath or dont get up until 10am if that is your pleasure. If that does not feel of any interest then now is the time still to look up things like youth hostel places, or a 3 or 4 day little course in whatever interests you, so playing bridge, or making pottery or walking in the Lake district. Just look around and see if there is something you always meant to do , or a place you have never yet managed to visit and get organised and go. Whether this is before or after christmas day, you can choose to use the actual christmas day as a preparation day , getting ready for your trip away. Enjoy being able to listen or watch whatever you want while you get things sorted. Or just use it as another ordinary day and clear up and sort out so that you move your holiday day to another one and if you go after new year to a good restaurant or hotel you will have much more choice and non stressed staff who will be pleased to see you.
I can see that you feel a bit shocked by the change and somehow had not expected it, but it may be a good thing to realize that nothing is set in stone and life can change in many ways. Think what you might enjoy first and then tell your husband that they are not coming and see what his reaction is. Maybe he will suggest a different way for you both. Perhaps his going to the pub was because he didnt really like a houseful of people. Might you decide to have a weekend away somewhere together before or after the actual christmas. If he has no ideas, still intends to just carry on his own way, perhaps it is a time to reflect on the way that you live together. Then you might start next year with joining a course, learning a new skill, looking in your local paper to find out what is available that you could enjoy and begin to form a life of your own. As far as we know we only live once, so you do now have an opportunity to think what YOU would like to do with your life and look around, think of your usual routines and see what could be changed, now you no longer have a family at home. You are free to make changes, whether that is what you do on tuesday or what time you eat your evening meal. Go for it, and enjoy it. Oh of course dont forget that many of us will be here at GN's on the actual day so you will still have someone to chat with. Let us know what you think you might do . Good Luck.