I dunno....we are 36' and 13'3". Wish we were a little lower and shorter.
Its my first camper and took some getting used to hauling it around, but my dislike is mostly that it limits where you can camp with it. I'm used to tent camping way off the beaten path. Can't get too close with our rig, but if you've got to spend time in it due to weather, the room and comforts are nice. The garage is nice too as had to repair a clutch on a dirtbike on a recent trip and had a nice clean workspace vs out in the sand, dirt and wind.
Clearance matters if you're going off road with it (at rear and at bedrails). If just pavement, you can get by with less.
I too bought a trucker GPS and a trucker atlas. And I've got an app on my phone which I use to double check clearances. I learned, the hard way, to plan my route ahead of time. Gas stops are at truck stops.