Sounds like a place where you do need a car.

I don't know that there is a minimum size place for being car-free though. I've been car-free in L.A., Little Rock, and an unincorporated community outside of Santa Barbara. With my current digs in Little Rock, I actually don't get to downtown Little Rock very often. I live in an area that has all my staple needs including two bikes shops, 4 grocery stores, a big box store, banks, post office, it has wildlife-filled creeks running through it and the big bike riding area just over the hills. All this within a mile or so. In L.A., again, some neighborhoods were better than others.

So, I don't think it's a particular size, but you do need to look for a concentration of services.