Depends on what you want. If you want to take up only one parking space, albeit a large one, the TC is the way to go. Hitching a fifth and hitching a travel trailer takes about the same amount of time and effort and that is one of the things you do not like about your TT now. A fifth has more tires, more brakes, and more wheel bearings than a truck with a TC. Yea, a fifth is bigger and has more storage but that is about it. I would rethink your premise about hitching and unhitching as taking the truck camper on and off the truck is considerably more effort than the minute or two it takes to unhitch or hitch a travel trailer. I have owned three truck campers and one travel trailer and prefer the truck camper for ease of maneuverability and the travel trailer for the base camp kind of thing set up in the campsite. If interior size is important re-think your options. If you like to carry lots of stuff in your truck bed the fifth is less desirable than the TT you now have. You should be able to reposition the axles and get a few inches more ground clearance with your existing travel trailer. That might help on the gravel roads. I don't get your comment about the hassle of hitching or unhitching as it takes a minute or two and with an electric tongue jack is almost effortless.
Northwood Manufacturing (Arctic Fox) makes solid TT, TC and FW products. Off road to Alaska and other places should not be a problem. They are heavy so get a stout truck.
The day I sold my last truck camper and bought the travel trailer I knew instantly I made a mistake. I think I should have purchased the trailer and kept the camper. After driving anywhere with the camper with relative ease and now being 55-56 feet long on the highway and having to plan every move with the truck and trailer......it is just not the same. With five feet or so of the fifth over the truck it would be a little better but not much.
My advice. Keep what you have and reposition the axles for more clearance or get the truck camper. If you don't like hitching or unhitching your travel trailer the fifth is not the answer either.