There are just the two of us and we're used to living in small spaces.
(Lived for a dozen years aboard a sailboat, traveled for many years in
a van camper). I loved our van camper as we could go/park anywhere and
gas mileage wasn't bad either. But when my husband had a stroke a year
and a half ago, we opted for the comfort of a larger Motorhome. On our
last trip, we were driving it VERY slowly to increase gas mileage (I
think Hubby is a little obsessive about this) and we averaged between
10 and 11 mpg on our 30' Winnebago.
I've been happy with both the van camper (my favorite) and the
motorhome. I'm a little wary of towing a trailer as I had towed one
once a number of years ago and the whole rig seemed to sway. But I'm
guessing that a properly setup rig shouldn't do this.