I had this problem and I realized it was on me and I hadn't seen how I was talking to them. For example, my DH and I choose a winter holiday and use it for vacation. The first year there was a huge blow out over not spending Christmas with them--and partially, I think, bc I asked. So go from

"Hey, DH and I would like to go to St Johns for Christmas. Is that ok? What do you think?"

To, "Great news! DH and I are going to St Johns this year for Christmas." *click*

The bonus also is you will be seen and respected as an equal, an adult. Might be a very gradual process, but well worth setting it in motion.

Just keep setting boundaries, OP. I had to go through something similar with my MIL. She threw an absolute temper tantrum one year when my husband and I didn't arrange our holiday travel schedule exactly as she wanted. But we stuck to our guns. You cannot give in to people like this or else they'll think they can continue to pitch a fit and always get their way. She still throws temper tantrums but we just ignore her and do what we're going to do...she'll either come around someday or she'll spend the next 20ish years with a chip on her shoulder.

My advice is to start your own traditions, especially because you say you have kids. This year, tell both families that you're going to spend the holidays at your own home. They can throw a fit about it but I bet your holiday will be a lot more relaxing and fun with just your nuclear family, and you can visit the extended family another time (i.e., the week before Christmas, or New Year's weekend, etc).

Good luck. This is hard stuff and I sympathize!