You didn't share, do you have a large stash? I think do the little things first, Like go through and eliminate doubles. Look at the space, can you go UP with your storage? Or, below your work surface? Or is your room under the stairs just for storing your sewing/quilting things. Does that mean you will be sewing at the kitchen table?
I used under the bed storage boxes that were great for storing fabric. Folded small with the folds facing up by color. It's just a thought. They slide easily and the tops keep the dust off. You just won't be able to see your stash.
A lot of people are down sizing these days. It can be done. And, I hope you have a lot of great fun planning and finding what works for you. Do a lot of looking on Google. I googled under the stairs sewing rooms. And, it was a great eye opener to see what other people have done.
I used to sew at the kitchen table. All my supplies were in my bedroom. When the kids moved out, I commandeered the sun room which was there hang out space. Boy, I almost have too much room. But, am determined to keep my fabric space limited. (I need to sew faster!! lol
Have fun. Down sizing is not bad. It will just be one small compromise. You can do it!!
