2001 GMC Yukon 1500 as TV

This is just my opinion. Pick the Buggy before the horse. We did the opposite and ended up switching both anyway. Buy the camper you want and try it with the yukon xl. The 5.3 and 4L60E tranny is very reliable. We just did a trip with my setup and my inlaws setup which is a 2000 yukon xl 4wd pulling a 5k loaded hybrid. Unless you change the tires on your TT most of them are only rated to 65mph. This puts your yukon right at about 3k rpms in 3rd gear with the 373 gears. I see no problems with your current truck to at least try it out. Even with a 6K trailer. Yes you will want more power and the mountains will slow you way down but it will do it.

My only suggestion would be to take off the current receiver hitch and get a heavy duty one. Those hitches are known to fail. Its peace of mind for a little over $100.