The problem with the Roland Go piano and keys, is that they dont fit into your aircraft lugage... and i think thats one of the things the OP asked for..
I have a feeling, but I might be wrong, that the Go Piano, only being 3 1/2 inches thin, would be allowed as carry-on. I mostly fly Southwest, so if not, I can check it on the plane.
The keyboard manufacturers should definitely create a board that folds or comes apart so musicians can travel without having to pay hefty overage fees and without compromising on missing octaves.