Last time my loaded camper scaled 6300lb on our trip, but I don't tow a trailer.
2017 F350 DRW handles that with no issues.
New trucks not only have stronger suspension than older ones, but aluminium bed and other weight reduction make the rear lighter, giving more cargo capacity.
The 440 HP (they increased it lately) can pull the camper and house behind.
The only issue I see would be 700lb tongue weight on the stinger.
That depends on stinger length can add 1200 lb on rear axle. With my camper I am 1000 lb below axle rating.