At the risk of being branded a heretic, I will suggest that this design is not as outlandish as the discussion so far suggests. It should be quite driveable, since it is simply a special-purpose semi-trailer of routine size, and likely quite moderate
weight. It is not much more expensive than the typical high-end bus conversion, is not a lot bigger than a 45-foot high-floor bus, and yet may be more functional for the target audience. It can be hauled by any conventional tractor (truck) of the appropriate class, and as a trailer has the advantage (over a motorhome) of not tying up that vehicle when parked (as it would be for long stretches of time).
I believe that while the floor area is larger than some houses (due to the two floors), the plan area (length times width) is exceptionally small by home standards.
Of course it's not
our kind of trailer, but the vast majority of travel trailers
sold today are quite large compared to ours... this is just the extreme case.
Interesting link. Thanks, Frederick.