I am from a small MN town there are a couple of cemeteries that fit your description, quiet, rural, off the beaten path. I know that each of them are checked on frequently by the Church maintenance person. There have been .... well I won't say problems but kids seem to like the idea of hanging out and they are discouraged from being out there after dark. If you were observed parked there even in a camper I would not be surprised if you were asked to move along. Now the church parking lot... if you asked to park over night, Ive never seen anyone turned away. I think in our church they will string out an extension cord and a hose for you. With that being said we do have a small camping area at the city park, I think there are 3 spots with electric and water, they do get filled up on occasion. The city Cemetery gate is locked, the outside parking area is right next to the busiest street we have, so it would not make a good place to stay.