This is a great discussion but mostly theoretical. My experience is real. I bought a 2010 3.7 Q5 new and have a towed a 2900 lb (Unloaded weight) travel trailer over 10,000 miles, climbing mountains and rolling on freeways.
It is an awesome tow vehicle.
Advice:
1. watch the towing capacity (4400 pounds) and remember that everything you put in the trailer (fluids, food, campfire wood, etc) and everything in the Audi (including your butts in the seats can not exceed the dry weight of the trailer plus the weight of all this cargo. Yes, you count as cargo.
2. Stay in manual tiptronic mode. Yes you have to shift. There are 6 gears, Try to keep the RPMs in the 3000-400o range. max torque is about 4000. Revs are good.
3. Use a weight distributing set up on the high with leveling bars and a sway bar.
The 2018 3.0T which I just bought has 8 gears and about the same torque package. I expect the same performance.
Have fun. Be smart. Manage your load.