The problem with the idea of a SRW truck is that at least 500 lbs of the payload will be taken up by the desired travel trailer tongue weight in tow. That really limits what type of TC can be outfitted on the truck and further restricts what extras you may want to carry on/in the truck (unless you go to high capacity 19.5" wheels immediately). When carrying a TC, a SRW will be as wide as a DRW, so the only time the foot print width will shrink is with the camper off the truck.
There are still many places to boondock with a 20' trailer in tow, but it will not be extremely remote. Think of where ever the trailer is sitting as base camp with excursions of 2-3 nights in the TC in more remote areas. If there are areas that are even more size restrictive, that's where your run around vehicle will benefit.
An example from one of our trips was a stop at a campground at the base of the Black Hills in SD. Rapid City had a festival in the heart of the town and even driving in a full sized SRW truck would have been challenging to find parking. Instead, we drove our dune buggy into town (which is less 9' long) and were able to squeeze into street parking right next to the entrance to the festival. Another example was our trip through Colorado Springs where we used the motorcycle to tour the Garden of the Gods and visit the town of Mineral Springs. Both those location were full of tourists like us and we had prime parking and access at both destinations due to our vehicle choice.
If off-road access is of interest, a little dune buggy or Suzuki Samurai/X1 is much easier than navigating 5 tons of home on goat trails...