If you can keep the loaded weight of the trailer at 5500 pounds or less You MIGHT be able to do it. 15% is the high end of tongue weight for travel trailers, 12% is probably closer to average. At 15% plus 100lbs for WDH you are at 925. Assuming the 1300 lbs payload is correct that leaves 375lbs for family. Not much, but 100-200 pounds over gvwr is not the end of the world, but never exceed axle and tire ratings. Are you a heavy family? The problem with running so close or slightly over ratings is that you will feel stuck and inflexible with things as simple as one of your kids wants to bring a friend along.
One thing to consider is darn near every diesel 2500 towing a fifth wheel down the road is over gvwr and most are severely over, but since it's a "heavy duty" people throw the ratings out the window.
