Your quest has gone from vans to small trailers with an apparent desire to have a small unit but you were looking for a mini toyhauler so you could take bicycles. If this is correct why not get a very small trailer (with a functioning bathroom) and tow it with a minivan or small suv which could carry your bikes, or if this is unsuitable mount a bike carrier over the propane tank or off the rear bumper.
Trailers wise, the a Palomini, R-pod, scamp, casita or one of many others would be able to be towed by something like a dodge caravan or ford explorer.
You would have tanks to allow normal functioning toilets, shower, sink and be self contained for even a few days off grid, no bags, no kitty litter, no gels.
