When we were a family of 3 (2 adults, one baby), we lived in 399 sqft. It was so easy to clean. But there were some compromises. Like always having to do chores in a certain order- dishes washed (no dishwasher) first so the sink was empty and ready for the "portable" washing machine to wash cloth diapers. But it worked for us for 2 years!
Funny, as soon as we found out we were expecting, my first thought was, "aww, we'll have to leave this apt.!" But having a small place ended up being a great excuse to deny "gifts" like swings, pack n plays, and various other baby crap I deemed unnecessary.