You'll get all the answers on this forum, yes, no, and everything in between.
Dry weights ARE meaningless. You don't camp naked and hungry. Every pound counts, including you, and you'll always be surprised at how much heavier everything is than you think. Even heavier than stated by the factory.
Vehicle tow ratings are based on engine, transmission, axle ratio, cab configuration. Make sure the rating you have is for *THAT* Yukon as it is configured, not the advertised maximum.
Tow ratings have catches too. They are based off an empty vehicle with no passengers. Every pound you add to the vehicle basically reduces your tow rating by 7.5 pounds. So throw a wife, two kids, and their stuff in the Yukon, and you have reduced your tow capacity by a ton or more.
Off the cuff, he's probably going to be pushing the limits of the vehicle all loaded up and ready to go.
