Tongue-in-cheek aside, I think a Porta-Boat would ride nicely off center on the Scamp's roof. My biggest reservation is its sailing ability, since I love to sail.
Another option I'm tossing around is a kayak or canoe modified to sail, possibly with outriggers for stability.
In an earlier life I manufactured Canoes. During that time I set up a prototype sailing rig for my 16’ canoe. It had lee boards, a mast step added to the floor and I used a paddle for the rudder.
It sailed very easily and I sailed it in High Sierra lakes, the ocean bays, as well as Mission Bay in San Diego. I wish I had a photo to show you but that was pre digital.
My 16’ canoe had a 36” beam. When the wind was pretty strong, I would let out the sheet so as not to tip too much. It is very easy to get the feel of it. I sold MY canoe with the sailing rig, but I now have the blue one I made for my sister (see below). Mine sailing canoe was white but out of the same mold.
I’m sure the Fold-a-boat would even be easier to sail.
Good Luck and get out there.