"Wells college offers a chance to take some classes at Cornell . . . "
Wells is very small–I think probably too small and too isolated given what you’ve said about his preferences, OP. We visited Wells 2 years ago, but D ruled it out based on size and limited course offerings (due in part to its small size). It’s half the size of Earlham.
Ithaca College also offers cross-registration with Cornell, and is much closer: right across the street versus a 40-minute drive over winding roads. But take a close look at how cross-registration works in reality. Find out how many students get to take courses that they actually want or need over at Cornell.