Socializing for kids

How often do you think primary school children should get together with other children? We try to have one playdate a week, but there aren't many kids where we are so we are thinking of moving so our kids could play wth other kids without us having to plan it. my son is 6 and if i ask him who he wants to invite over, he often only wants one or two kids from school, but if there were kids near us, he might just run off and play with them. do other kids fuss about who they like and don't like? how important do you think it is for school aged kids to live in a place with other kids around? thanks so much! it's hard to move, but maybe it's necessary for our kids' social lives to improve without all the hassles of playdates!