Been there with my husband. Granted we don’t have children yet, we had to work through this when we got married and wanted to make our own married “family” traditions. Christmas in particular, too!
Does your husband express any desire to start any new family traditions with you and your family? You only mention that you know he will be hesitant to change anything almost for fear of how his mother will react. I’ve read some of the updates and you say he sometimes just side-eyes your comments about new traditions the 3 of you…. But has he ever himself suggested any traditions or is it just all you?
When you calm down a little bit from this rant, have a casual conversation to see if he would want to do some new Christmas Eve/Christmas Day traditions with your new family and go from there. Make suggestions and come up with ideas on how you could get what you want (like staying home Christmas Day), but how you can also make his mom happy and of course see what he wants. As cheesy as it sounds, I really encourage you to use the words “I understand” and “I feel” .
“I understand you want to spend more time with your family, and I understand that Christmas is a big deal to your mom. However, it would make me feel really happy if we could do XYZ Christmas morning/day. Since that would make me feel really happy, what if we do XYZ with your family for Christmas instead. I understand how important it is to you, but XYZ is important to me too, so can we compromise on this a little bit?”
I knew my husband would be hesitant to change up the traditions we previously had with his family once we got married, but it wasn’t because he didn’t want to put their needs/wants over ours or mine. He wanted us to do our own thing too. Yes, essentially he was “scared” or he feared disappointing or upsetting her or making her feel unwanted, which is totally normal to feel. Maybe your husband feels like that? Have you asked him?
Changing traditions is a huge change for all parties for a variety of reasons. I definitely had my “tough shit, this is what I want to do this year, screw everyone else” attitude but I talked to my husband and quickly changed my attitude once I knew how he felt and where those feelings came from. I went from “tough shit” to “oh, okay. I get it, so I’m okay doing this and that so we both get a little bit of what we want.”
ETA: based on your updates, if your in-laws truly are the “i’m not compromising. this has been tradition for 1000 years” type of people, then thats when you and your husband need to have a good talk and put your foot down. it isn’t fair you are the ones compromising with them all the time. trust me, we stopped compromising and used the “sorry, no that won’t work for us” line a few times and its amazing how much more flexible my ILs are now.