Where I'm from, most people I know live in smaller apartments than these houses, often with two kids. The trick is to have the minimum number of rooms (only bedrooms + bathroom + kitchen + living room - or fewer), and to allocate a good portion to the living room, which can be adjusted according to the needs of the moment. Many households have extendable dining tables, foldable chairs (either hollywood-style or fully wooden), etc.

Having a couple stay for three months would be troublesome, but dinner for eight or ten is perfectly doable.