I still sometimes buy because I like, but right now, I'm trying VERY HARD to restrict myself to fabric that I need to finish a project. I have so much fabric and plenty of UFOs to complete. However, I go through ALL my stash twice a year. Most of it is in Rubbermaid containers. I can't understand why 90% would have been damaged - they got into ALL the containers? So sorry that happened.
My suggestion, since living without a stash makes it darn near impossible to do some things, is to either join swaps (where you will get a variety of items) or have a stash, but limit it to ONE Rubbermaid container and make sure it is a foot or more off the floor. It should do fine in the garage provided you actually regularly access the stuff. My Mom did this when we lived in Massachusetts, so I'm even familiar with the climate!
I have a cutting table and am trying to work my stash down to the 12 half boxes that fit on the shelf under it. My sister has a tiny, tiny sewing room, but she has that cutting table as well and stores her fabric underneath.
By the way, for a good laugh, I just finished using up fabric into pillowcases that my Mom bought at Giant in Framingham in the mid-70s.