My long Lang is 4 feet wide, and built with 4 sawhorse style legs screwed from the inside to the outside. It has 4 migratory board tops, so I uncover only a fourth of the hive at a time.
The first top has two shims lifting at the short end for a migratory top style top entrance. And there is a single piece of plywood over the whole so rain won't seep between the 4 top pieces, although I wonder if I can do without that, or at least replace it with something lightweight such as a sheet of aluminum.
Deep foundationless langstroth frames are used, with the wedge broken off and re-glued sideways for a comb guide.
When the feral colony moved in, I placed them at one end (where the top entrance is) and the have been steadily filling the hive towards the other end. About half full now.