Sorry, little late to the party, and OP has probably purchased a TW already.
I tow our K-Z 16BH with a 2016 Kia Sorento EX V6 7 seater. Weighed the trailer loaded for a week long trip, empty tanks, battery and 20lbs propane on the tongue, and came in at 2832 lbs with tongue 336 lbs. I have not used a WDH yet. When towing, we carry most of our stuff in the trailer, distributed as well as we can. There's only passengers (me, wife, two girls 10 and 7) and snacks/drinking water for the drive in the vehicle.
So with the above setup, the towing is OK. I tow 90-100km/h so 55-62mph and biggest hills are just over a mile long at 5% gradient. Last summer we did camp in a spot that was at the bottom of a 15% bit washed out gravel road and I had no trouble pulling the trailer up from there, but that was obviously going pretty slow. While the Sorento can tow the trailer we have, I wouldn't want to much heavier trailer with it and would prefer some other vehicle even for our current trailer and our next vehicle will be something bit more capable when it comes to towing. Some better designed/built 3500 lbs trailer might tow better than our cheap plywood shack on wheels, but I am quite certain that the marketed 5000 lbs trailer would just about kill a Sorento.