I live in a somewhat rural area. Houses are far apart and I don't really know my neighbors
BUT, we have plenty of playdates. We have meet like-minded friends via Meetup, Holistic Moms Group and some Yahoo homeschooling groups and we see each other a few times a month. I'd say on average my kids (5 and 2) have at the very least a playdate a week. We arrange it and take turns at each others houses. Could you do something like this?
it was just dd and me. and no other kids. dd is more of a people person so we moved.
really we need just one more family. not more than that. but in the rural area we didnt even have that.
so it really depends. if your sons enjoy each other's company and are happy with that then there is no reason to move.
i think even having another sibling would have helped dd. she got tired of playing alone - even though she loved the outdoor.
now we have people but not the outdoors - or that much access to the outdoors. we miss the mud.