Two mantras are constantly being repeated here.
Buy enough truck for your next, (larger) trailer
and you will always pack more than you need.
Neither are true.
When our kids left home we downsized from 29 ft to a 23 ft HTT.
When I saw the pile of stuff we were taking from one into the other I wash shocked, surely the people claiming 1000 to 1500 lbs of stuff were correct.
Not So! our entire kitchen pots pans tableware and appliances,came in at just under one hundred pounds, our bedding came in at under 50 lbs. tools about 30.Rv stuff chocks blocks hoses power cords are by far the heaviest category at just over one hundred pounds.
We were right around 6 to 700 pounds of cargo all said. We do not need everything in the world but we certainly are not minimalists either.