I had a 2016 Durango R/T with the 5.7 Hemi, with a payload of 1350lbs and a tow capacity of 7100lbs and I pulled a 6700GVWR TT.
As their are only 2 of us the Durango did a great job even pulling 6-8% grades.
The problem with the later model Durango's is it's uni-body construction and the hitch tongue weight capacity is only 720lbs.
Even though the trailer I bought showed 413lbs of tongue weight, when I weighed the TT loaded to 6300lbs, with WDH the tongue weight was 770lbs. Upon discovering this (safety being a major concern) I did not want to exceed any limits with my towing vehicle.
Long story short figure 12-15% of the trailers GVWR as the weight of the tongue.