FWIW, I have a 9000W for power outages: 1652 SF house, 2000 SF of shop, but no AC.
Runs everything just fine, though I do scale back activities like laundry & microwave at those times.
It's likely close to the limit, judging by the load I hear from the generator if I run those items + the normal stuff.
Seems everyone else has a lot larger setup than mine, but maybe this will serve as a reference.