Even if that v6 Tahoe was empty besides the driver and the trailer was also as empty as it was on the dealers lot you cannot tow that trailer. The wind resistance alone will make keeping up to highway speeds difficult on flat land, let alone in the mountains.
Add 800 pounds of people, pets and groceries and another 1000 pounds of water and camping gear and you are approaching 10,000 pounds. Don't forget the 100 pounds for the WD hitch.
How much trade-in value will the Tahoe have with a blown transmission? You should get a capable truck first and then buy a trailer that is appropriate for it's abilities. And for both of those trailers a 3/4 ton truck is needed.