help choosing: Arctic Fox of similar 'medium' TT

Have you considered a toy hauler? You can fit two twin sized foam mattress pads on each of the drop down queen/sofa platforms and create 4 separate beds in the rear of the camper for kids plus the main queen up front. Toy haulers tend to have much larger tanks and most of them also have on board generators that run off on-board gas tanks. In terms of boondocking they really do have some advantages over your standard camper trailers. The length could be an issue, though.