Hi spacegirl,
I am not a JW but my wife is, rather liberal though, probably considered spiritually weak by many in her cong. We have two small children. For me marriage is about loving each other and accepting who we are. This involves compromises in our life together because there are always differences, not only the religious ones. We have different hobbies, different priorities on vacations etc. But we have made the decision to build a life together for us and our children, so we have to make it work. And it does work! Mainly because we always come back to "We love each other" and "family well-being is our top priority". And starting from there we find compromises. But first we need to know how important certain things are in each others lives.
Examples: I like birthdays very much and I want them for my children to celebrate freely. So we do celebrate them, just not with a big party or inviting lots of people. I like Christmas, too. But for me as an agnostic it is mainly a good occasion for quality family time. So there is good food, gifts, a lot of talking and playing together but no tree in our house. It's not that high on my priority list but it's high on hers to not have one. So I give her that, and on the other hand she gives me other things. We usually visit my parents or my sister during Christmas für a few days so we do get to see a tree after all.
So is your husband willing to compromise, too? Does he recognize how important the tree is for you and act accordingly? Try to figure out what exactly he doesn't like about it. Is he afraid that others JWs find out? I wouldn't force the tree, but I admit compromise is difficult here. Maybe put up a tree only every two years? Or always go on vacation during christmas and put up a tree in your vacation house/cabin so it doesn't have to stand in his house?