My 2011 190 varies from 7 to 9" underneath. There is a lot hanging down there that can have a lot of expensive damage done - tanks, plumbing, genset. Of course, it can be driven on dirt and gravel roads - as most campgrounds are dirt and gravel but it is not an off-road vehicle and should not be driven as such. I would not go into deep snow and I would avoid seriously rutted, muddy, or potholed roads. I had concern when I had to drive through a deep puddle on a road that I could not go around or go back from.
For a while Roadtrek offered an option for AWD that was done aftermarket (not by Chevy). It was made clear that while it was AWD it still was not for off-roading. That option is no longer offered.
Yes, some have installed lifts including air cushion lifts but you don't really get off-roading clearance.
If you feel that your truck camper limits where you can drive, a Roadtrek is going to limit that even more.