That seems a pretty common pattern for the semi-rural New England area I live in as well. I lock the house at night or if I'm headed out for an extended period but I don't really worry about it. If the house is all opened up on a summer day I'm not going to shut everything up if I'm going out for a bit and certainly not if I'm around my property somewhere.
If someone wants to get in to steal something, they're going to get it done. That could mean a broken window, a broken door, or it could mean nothing broken at all. There's no-one within listening distance to hear a window break, so they're not going to get caught that way. But, your neighbors know your cars, and the sense of community commonly leads to a quick "hey there's a brown Buick outside your house, is that you guys?" call/text. There aren't very many "drive-by" robberies; houses are so far apart and all it takes is one person who sees a suspiciously slow driving car, or a car visiting multiple driveways, to call the police. Oh, and if you thought no one was home and you're wrong, there's a great chance they're armed, and they saw the car you used to get there. And the police are never busy, so they'll be there in minutes.