One might say that a truck + trailer is a loosely coupled shelter/transportation system, while an RV is tightly coupled...
@Freedom’s right, a lot of good boondocking spots are getting blown out in the west. That said, the amount of possible boondock spots out there is enormous - it just takes more skill and experience to find those spots, and to start to know which areas are likely to be blown out. This is another reason to go with a smaller rig, and potentially high clearance or 4x4: you have greater access to spots that other people literally can’t get to.
If DW and I only had one rig / vehicle between the two of us, we’d go nuts. I have a truck, my trailer, a motorcycle, and she has her van. Also a big tent. We often sleep in separate rigs. That’s not a totally optimized situation obviously, we’re working on it, but not being attached at the hip is VITAL for long term rig life.
A YouTuber couple with a skoolie and a toad (“towed” vehicle) drive separate when they travel. Commenters have them a hard time, “where’s the love?!”. They made a video and said “we live within arms reach of each other 24/7. The alone time apart we get when we drive is precious.”
There’s so many different ways you can do it, and it’s so personal, it’s tough to design the right system without experience. And if you’ve got a SO that’s a little resistant, the danger is in guessing “wrong” first and then she’s turned off to the whole idea, when a slight tweak would have been delightful for both of you. If there’s any way to approach it as a couple with this mindset of “okay, we’re going to give this a go, and this is going to be our first guess at how we want to do it, but we recognize we might not nail it the first time, so we’ve got a plan b and plan c to iterate the system”.
Plan A = 25’ RV plus one of your current cars (tow it or drive separate). Maybe rent to try first.
Plan B = high top and minivan
PlanC = ...
An extroverted van friend had a total blast going to a van person meet up. Descend on bend I think. Something like that might help your gf get over the stigma (“look at all the cool people here...”).