Some RV's have an empty space over the cupboards in the kitchenette. If you do, can you get some of the fabric storage bins from Ikea to store soft things up there. Maybe your tops or batting to free up some space. How about a couple of suitcases. You could put a couple of projects in one and use the side of the suitcase for another workspace on your knees. When you want to store the project, just stick it back in the suitcase and it will be easy to move with the handle? Do you have room to use the hanging shoe bags on the back of a door? They are great for storing sewing notions and scrap strips etc.