Previously, we've always ended up on the living room floor... and I've been a trooper and didn't mind. But this Christmas, I'll be 7 months pregnant... I'm not sure sleeping on the floor will be comfortable. (Plus, this is a high-risk pregnancy).
I suggested to DH that we get a hotel, but he said his parents would be offended because we're not all "together" Christmas morning to wake up to breakfast.
There seem to be a few different issues all thrown in together here.
You've slept on the floor in the past, but I didn't see where they said that you, now pregnant, would have to sleep on the floor this time. Are you assuming that they wouldn't make better sleeping arrangements for you or did they say this would happen again? I would imagine that they are reasonable people and would give you a bed - you are pregnant after all!
On a go-forward basis, this situation has to be fixed not only for Christmas, but for all future visits. When you travel to see them, sleeping on the floor isn't acceptable (unless of course, this is what
you want to do).
As your family grows, so will your obligations...school calendar, sports, etc. It may make more sense for them to travel more often to see to you. If they choose not to travel to you, then oh well, its their choice, and not your obligation to keep carrying the travel burden.
Time to break with the parent's tradition of having to have everyone there xmas morning and time to make your own traditions with your own new family (DH, yourself, and baby).
Time for DH to stand up to his parents. Time for change. Better now than letting this get ingrained any further.