Dartmouth is a fantastic school. Beautiful campus, lots of little nooks for friendly gathering, socially normal students, great reputation among large companies like banks. In fact, in recent years Dartmouth came out on top for the highest earnings by graduates. Had the current coach been there when we visited, our daughter might have opted for it. But even if you dress warmly, the weather is an issue. Think deep slush--lots of it. Also, given its remote location, the athletes always have to travel pretty far for conference meets and other meets for that matter too, ie. in Boston.
Princeton is very tough academically--they have grade deflation and those junior and senior papers everyone has to do. But don't think Stanford is a breeze. It isn't, because its acceptance rates are right up there with Harvard's. The majority of athletes are just like non-athletes--very bright and academically accomplished. National Merit Scholars and such. Unlike with helmet sports, the school doesn't really have to lower their standards for distance runners.