I was towing and launching my boat, which weighs about 6,500 pounds on the trailer, with a crew cab dually hauling an 11' TC. We sold the TC after our third child was born because it was just too small. I've been looking at older Super C motor homes and it looks like most of them would probably be fine for putting the boat in and out. The body seems to rise up in the rear, I guess to improve departure angel, and the ground clearance is decent for going over the angle where the ramp starts down.
I'm starting to also look at some class As but they look much lower with less ground clearance, break over angle, and departure angle. I'm curious if many people launch and retrieve boats with them.
Taking a second vehicle or having a complete stranger use their truck to launch the boat is not an option. My wife is not comfortable driving much more than the non-towing Suburban. We like to explore lakes that are 3, 5, or even 8 hours from home so making 2 trips their and back is not an option either. I grew up on a farm and spent time as an OTR truck driver so I have no problem maneuvering the rig, just wondering about the physical abilities of one to navigate a boat ramp.