115 gallons for a power cat for a week mostly with genny running at night - that sounds about right.
The OP states their AC was broken. I wonder if it was broken the whole time or just that it broke at some point? I don't see how OP did somewhere around 140 gallons unless the genny was running and certainly not much point in running the generator all night if the AC isn't working. So that's odd. The other option is the tanks were not full when they picked up the boat. Which given the list of things that should have been caught before the boat went out a possibility.