Towing a 39' TT across country? Possible or no?

I love my 3/4 ton Burb and highly recommend the 8.1L. But the wheelbase is still 130", less than every HD pickup.

A 1-ton van would offer far better personal space for all that travel time with 4 rows of seats. You can find them for far less money for similar condition SUVs.

Consider what types of campsites you want to stay at. There are many 40' motorhomes traveling across the country, but few of them stay at the state parks I frequent.