Here's the update I promised...
We made it to Albuquerque in one piece and with our sanity intact!
We LOVE the Yukon...it meets our need perfectly...up Raton Pass we only slowed to about 50 mph and the rest of the way we averaged 65 mph and got 12+ mpg overall. Towing was uneventful and the 7 hour drive with Mr.InsideOut (I-don't-like-roadtrips-until-I'm-there) was actually pleasant! Yipee!
Gives us something to look forward to next season...getting ready to winterize this weekend.
Thanks to all the advice...