Doug, your setup is pretty close to what I already own. I have two 50s hinged to be a portable 100w deal. I have two more identical 50s in the garage. I could put them on the roof. My first thought had been to go bigger on the roof. It would be good on our winter trip to the SW, but not much help out east. I think I will stick with the portable pair as long as I can.
They are not that much hassle imo. They fit roughly a 2 foot square space in storage. If they get stolen I'm not out much, so I don't obsess about locking them up.
Anyway it seems like your approach might be the best compromise. But I hope we hear from more shade campers with solar.