First off, forget all the bravado talk about how much power your Durango has, as in how it laughs at trailers... Power has nothing to do with being able to tow safely and under control. In fact, having a lot of power in an other wise towing challenged platform can just get you in trouble faster.
Some well regarded TVs in the past such as the early Dodge/Cummins and Ford Powerstrokes were far more capable than your Durango, with much less power.
That said, you do seem to realize that your limitation will be payload. In my situation, I have a 1 ton dually CC, So I don't pay a lot of attention to it.... But you NEED to KNOW your numbers everytime, as you will be cutting it close. This is difficult with a TT, as normal usage can drastically alter the TW of the TT in the course of a trip. Propane gets consumed and disappears, FW leaves its tank and ends up in the black/grey tanks. Food/drink gets consumed and leaves the pantry/fridge, and ends up in the black tank. Clothes get used, an leave the closets ending up in the hamper etc. Many other items may ride home in a different location than they started the out on the trip.
So you need to know your weights..No guessing or estimating. Get it weighed (Durango and TT) ready to camp, at the heaviest you will ever be. Figure out where your TW needs to be. Then get and USE a Sherline TW scale Everytime you hitch up. Doing this will allow you to make any needed adjustments BEFORE getting on the highway and finding out the hard way that your TW is too low.
Be safe out there.
Happy camping