Another voice for keep what you like. If you still have to release some of your first choice fabrics to keep what you really want, it gives you a smaller base to go through. That it is a time motivated set of decisions, makes it harder in some ways and easier in others. I know it only sounds easy -- decide how much you think is reasonable to take and keep to it, consider where it is to go in the new house or the cost per box to ship/store, or whatever other considerations you have to take in account.
I've been quilting/collecting fabric since 1978. Moving around a lot as a young adult helped keep the stash down but I've been in this house for some 25 years and the collection has grown...
If it's any comfort, I went through a large purge a few years ago and there is only one piece I regret (I knew it was a challenge to me but decided to push myself). But that out of all I gave away that I only regret one is pretty darn good! So far it's been about 10 large black plastic garbage bags to many good groups, mostly through Craig's List wanted ads. Textile students at the local art college took all my non-quilting. A primary school art teacher took the crafty stuff. A church group took a bunch of orphan blocks, unquilted tops, and fabric. Bag went to the girl scouts. Another to a 4-H fund raiser along with a lot of books.
I'm building up to another purge in the next year or so. It's really nice to have the advantage of time. Wish you the best in your move. Remember to stop and take a deep breath every now and then
