I absolutely get where you are coming from and its not controlling. And all those saying your DH can take the DC away at christmas for 11 days and you shouldn't be bothered are just being obtuse.
I think most mothers who had only 4 days off over xmas and their DP wanted to take the DC away for 11 days would not be happy about it. I for one, would like to spend all if not most of xmas holidays with my DC and my DP. But like you would compromise on a few days if it was important to my DP. You compromised, but he abused that. You said no, thats not on, and hes thrown his toys out the pram.
The fact you agreed to 6-7 days is fine, but your DH has the arse about it and has now decided to just go on his own but actually over xmas day. I think that is really really shit of him.
If there was some underlying thing such as his parents were very ill or very old or really really wanted to see him, thats different. And you'd know about it.
It isn't. He is having a strop and basically saying a big fuck you to his family because he didn't get his way. he is willing to disappoint his DC on xmas day of all days just to spite you because he didn't get his way.
For me christmas is about spending time with your family and yes you fit in seeing parents and other relatives where you can. But the priority should be your actual immediate family unit.
Travel with covid at the moment is hard and really if its not necessary, why do it. You are seeing them in february, thats hardly years later. They live in another country, so its hardly a quick trip.
Factor in the MIL is flaky with the DC's safety. trust me, I know where you are coming from with that one!
I think it is very unreasonable for any parent to bugger off over xmas with or without the DC leaving the other partner behind if both are not in agreement and there is no urgent or valid reason to do so.