A few years ago, we were staying at an RV park in California when a couple pulled into the site next to us with big DP pulling a popup camper on a new Dodge Ram 2500 pickup where they used it for the same reason you mention. The only reason I am mentioning this is that once I started talking with them, they too were considering a Class B ...a Roadtrek to be specific.
They decided against the Roadtrek and decided to go with a popup truck camper because of the versatility. When they didn't need the "adventure vehicle," they could take off the camper and stow it on their property at their home base (they weren't completely full-time but close and had one of their children staying at their home with acreage) and just use the truck alone for a variety of reasons. e.g. commuter vehicle, a truck for hauling stuff, or just a toad when the camper function wasn't needed.
It was actually a neat little set-up after he showed it to me in detail. It had a cassette toilet and a make-shift shower area. He said that for the two of them out for a few days of exploring, it was perfect as it had everything they needed for those few days away and had 4WD and lots of ground clearance.
They had a cassette-type tank for the grey water also. I asked him if he minded the portable black and grey waste tanks and he said that he didn't have a problem with it and it was just perfect for outing of five days or less if used conservatively. While we were there, they were gone for two outings. One was 2 or 3 days and the other was 4.
It needed no modifications to tow 4-down and was a bit lighter than a Roadtrek. All three of the full-sized pickup manufacturer's trucks (Ram, Ford, and Chevy/GMC), I believe can be towed 4-down without modifications.
He was a retired engineer so he told me that he actually designed and engineered the tow bar himself and had it custom made. It was the most robust tow bar that I've ever seen ...I wish I had taken a picture of it.
The RV park we were at did not charge him for the truck camper. It fit in the same space that a normal toad would and I didn't see them plug it in to the electric pedestal at all or if they did, they did it discreetly at night.
This is the one he had called Four Wheel ...go HERE
It's a California company and they make a variety of models with different options. I'm thinking that other manufacturers make similar popups.
Just something that you also might consider.