If you’re convinced that a pop up will do, you might look at a Caribou Lite. Last weekend I was in the Valley of the Gods camping and talked with a guy who was living full time in his Caribou Lite on a Ram 1500. His Caribou Lite Had lots of options (outdoor shower, cassette toilet, two awnings, outdoor features, etc.). He was fairly happy with his setup though he was pretty sure he was overweight for his truck. The Caribou Lite is lighter than a similarly equipped FWC.
I have lived in vehicles through winters while in grad school (old VW bus a couple of winters and an Isuzu Trooper a decade later). Sounds romantic, but unless you have somewhere indoors to hang out at, it can be a drag. If you’re overwintering in snow country, forest roads are often closed either by the Forest Service or by nature. Waking up to find out that it snowed heavy last night and you are boondocking can ruin one’s day before it gets started. Summers were easy, winters are tough.
I currently camp in a ATC Ocelot.