When I had my TT with my family of 4 I was 2k lbs more than the dry weight. I do pack on the heavier side which is why I say to go with at least 1500lbs more than the dry weight sticker. Fifth wheels typically hold more so it’s easy to pack things into them. My TT was an oddball in that it had a 4100lb CCC of that I only used 2k lbs. I never travel with full tanks and only about 10 gallons of freshwater.
With that said anything you look at add at least 1500 lbs to the dry weight and then figure 20-25% for the pin weight.