For a few months at a time, due to various housing issues, I’ve had as many as 10 people (6 kids—no babies or toddlers) living in my 1,300SF house. MUCH more pleasant after we added a second bathroom, but entirely, absolutely fine, either way. Normally we were 4 people, 2 dogs, a cat, a parrot, and a ferret, and when it’s just us, there’s plenty of unused space.