So, just doing a quick comparison, both the Audi Q7 as well as the MB GLS450 have a longer wheel base than the standard length Escalade (or Tahoe).
The Benz has 7500 pounds towing capacity, and the Audi has 7700.
Even the Jeep Grand Cherokee has a wheelbase within 1" of the Escalade (and is rated to tow what you are asking for).
I haven't towed a travel trailer with any of the above, but it seems that the specs will allow you to do so safely.
I would still recommend taking them out for a spin to see if the performance of the engine is something you would be happy with.
A few years back I test drove a 3.0 TDI Q7 with the thought of picking it up to tow my boat. To me, it was under powered. Newer engines/transmissions combos might have changed things. The one I test drove was probably about a 2010ish model.