Get your tickets to THE BIG THING 2026!
Beat me to it.I think the biggest difficulty with this kind of thing is that some of your requirements are mutually exclusive. You want something that will sleep your family and have a bathroom but it also needs to be able to go off road. Bath and sleeping requirements mean HEIGHT. You have to be able to stand up, at least 6' of headroom. Unless you have a pop up that's a tough thing to accomplish without getting something that is tip-over prone.
Maybe you're trying to do too much with one platform? The simplest solution to your dilemma, IMO, is one that hundreds of thousands of people (or millions, I don't know) choose every year and that's a capable tow rig + a travel trailer of appropriate size.
Now it's true, that "combination" is not as capable overall - you aren't pulling a travel trailer over a rugged trail (hell I wouldn't pull a small Teardrop over one.) But if you can modify your method of traveling, it could work. Essentially, you would "base camp": That is, go to a specific location and set up your trailer in a "base", then unload everything you'll need to live while using the tow vehicle to explore.
Is it as versatile as an all-in-one arrangement? Absolutely not. But it also requires a lot less compromising in terms of comfort for your family.
The nice thing about the tow rig/trailer combo (full disclosure: That's what the wife and I have) is that it allows you to maximize each separate portion of the whole setup without compromising the other portion: IOW you can have a trailer big enough to be comfortable to be in AND have a vehicle with decent-enough off-road chops to get you far into the back country. An all-in-one arrangement forces you to prioritize one over the other.
Yes, in a perfect world, we'd all be driving vehicles that could run 4+ off road trails, sleep 5 comfortably, has a full shower and bath and gets 40 MPG. But that vehicle has a perpetual motion machine engine and unicorn-skin seats.