Your choice of tow vehicle and trailer sounds very acceptable to me. For the type of traveling you are doing, you can't have too much truck! But nothing wrong with going with a longer 5er. Our TT is 35.5 feet long, two opposing slides in the rear living room, stand alone furniture (no dinette), perfect for 2 people! My tow vehicle is a 3500 diesel dually. Many think that's an over-kill, but the trouble free towing is worth every bit of it! It's great when you can tow something and not even realize it's behind you 75 percent of the time. Really, the only time I sense the trailer behind me is when making turns or backing into a campsite.
One more thing.... if you can find a truck that has the integrated brake controller ... you'll not regret it at all. Those things are great. Truly, the truck and trailer operate as one unit. He harder the truck brakes, the harder the trailer brakes. In town where driving is slower and stops are more frequent, the brakes respond on the trailer like the trailer is not even there. Combined with the exhaust brake, and to tow is marvelous.
I personally suggest looking for a truck that has all 3 of these features already installed: Integrated Brake Controller, Exhaust Brake, and Cruise Control. (Turn on all 3 and you almost never have to touch the brake or accelerator peddles unless traffic forces you to slow down).
Good luck on your adventure! Sounds like a fantastic journey!