I have a lot of fabric, but it wouldn't fill a trailer. My sewing room is about 13x14 feet. I have shelves on one wall that are 8 feet long and they are floor to ceiling. 5 of the shelves are fabric, folded and oraganized by color. The other 3 shelves are bins with projects and scraps sorted by color.
I also have a cd rack that I just added that holds fat quarter bundles that I am just not quite able to dismantle yet.
I have no room for anymore fabric in my room!! I am full. But I am happy with it all.
I make only king sized quilts now, for the most part. I do finish things. My goal is to complete three a year.