Deonb, My Quadra steer Denali is over ten years old with only 75,000 miles on it. Won't buy another one until they offer Quadra steer again. I love the Quadra steer. But I only drive it when I absolutely have to use it as a truck. Over the years I have gone to great lengths to fit things into our old Model S so I didn't have to drive the truck. When I need a truck I use it.
After many road trip miles in Model S cars I never imagined that Model X would be practical for towing even 5000 lbs for any significant distance. The range when towing has to be brutally short. So your decision to buy a proper tow vehicle is wise. I never envisioned the X would be a logical tow vehicle for heavy loads over long distances.
The old saying, proper tool for the proper job applies. Your diesel Denali is a great fit for heavy towing.