I just remembered your thinking of renting an rv and my advice is don't because as you said, that'll buy a lot of gas. Since your truck has the power to pull the TT over the mountains you're good to go; just make sure your brakes are in good order. Even if you get near the MAJOR national parks there are places you can stay and park for a time so reservations are not needed unless you want them. We've been to Y'stone, G.Canyon, etc. WITH reservations but we stayed for at least a week on those occasions. On the trip I just mentioned, I was able to find places to park the MH for as long as we intended to stay with no real difficulty. We even found a place to park and visit Yosemite after circling the village lot one time. I thought that would be impossible but it worked. With a bit of planning and the ability to adapt you can have a great time like we did.