Does your van's curb weight include fuel ?
Probably not. I'd run it to one of the scales 'roundabouts to get a baseline on what the actual curb weight is if I were considering running with a load that full. As it is, I've done quite a lot of remodeling on the house using just the minivan for transporting supplies, just buying things as I need them. Few sheets of plywood and drywall here, a bathtub there, etc. The heaviest load it's probably had so far is 8 adults at once.
How drunk were you?
I'm quite aware what my wife weighs (not much), and no alcohol needed.