Try Burlington, Vermont if you want to be near a city with open-minded people yet still go toward the rural, country experience. It's usually possible to find rooms or campsites at the last minute during that time of year because it's considered "off-season", but I still recommend making reservations if you want to get the kind of accommodations you prefer. There are many festivals and art-gallery type events going on up there, and lots of decent-to-excellent, yet not very expensive restaurants.
If you don't want to drive all the way to the top of VT, try Brattleboro or Bennington. Again, the same caveat applies to reserving accommodations, but these towns are less "metropolitan" than Burlington but lean more toward the "quaint New-England town" kind of setting. You can find lots of museums (Robert Frost House and Ethan Allen come to mind immediately but there are others), swimming holes, farmers' markets, and good restaurants in this area too.
Should you decide to do this, you must stop in Shelburne Falls, Massachusetts, on Rt. 112 off the Mohawk Trail (google "Shelburne Falls potholes"). PM me if you want more specifics.