Interesting, but being 8' to 10.5' wide would be uncomfortable imo. Different strokes for different folks though. Also wonder about the corrosive effect of exposure to salty air and water on the steel containers.
What you do with the Intermodals is join them together (or stack them) to give you the space you need — much the same way double-wide house trailers do. If you join five 40x8-foot containers to a single 40x8-foot container (each one is 320 square feet) together, you get a rather nice 1,920 square foot (40x48-foot) living space. Another idea is arrange four 40x8-foot containers in a square with an open center. The containers can be the living areas off the center courtyard that can be totally enclosed and arranged internally to suit the owner's taste.
Now, I'll grant the containers are homely as all get out, but they are designed to go together and stack on each other or side-by-side or end-to-end. I think that there's a real and untapped market to recycle these containers into sturdy and available housing.