Doodling on paper I find the axle (s?) placement could be a problem with door swing/opening.
I like the idea as I have four kids and we would like to do a family trip across the US when they are all old enough to remember it (before they move out) My Dodge Grand Caravan (or whatever will haul all six of us then) should be able to pull a trailer like this and unlike a standie the drag wouldn't be there.
I couldn't find anything like this by searching, if there are threads please let me know.
My other idea is even crazier, putting one "room" up above the foot areas of the other two rooms, and turning the rear sleepers backwards. That compromises the galley shelf area and would kill the advantage of the low profile of a TD though, as well as giving up storage space (three girls).