Hey T, sorry this is cropping up but you know neither of you have the best of conflict resolution skills. Yours have definitely improved but it's hear impossible to change that dynamic when both people aren't involved in the change.
I hear a lot of I I I, me me me in the conversation, very little about how the 2 adults involved (along with the families) can make this a peaceful, loving time for the kids. I would encourage you to think about that, because kids those ages don't give a flying flip about Christmas and what day of the week it is. That's adult ego that wants to have certain "special" days. Is that helping you or the children?
While what W is asking looks selfish to you, what you're asking probably looks selfish to her. You both have to be prepared to give. What if you started a conversation with "W, how can we arrange this so our kids have a happy Christmas and we get to enjoy our time with them?I know what I'm proposing might sound selfish to you, as yours might to me. How can we work this out?"
You can make this what you want it to be. I'd ask to have them for the week after Christmas (or whatever)and could start to build new traditions with them. Something that's special just for the 3 of you, that you can do every year.
Just keep in mind whatever you decide that this is about time with your kids, not winning or losing over a certain day.
Me 57/H 58 M36 S 2.5yrs R 12/13
Let me give up the need to know why things happen as they do. I will never know and constant wondering is constant suffering. Caroline Myss