I also think that I would fly to Boston, Logan airport. Then I would rent a car to get to UNH, U.Mass, and Wheaton College (assuming you want to visit the one in Massachusetts). Boston College would be relatively easy to visit while you are in the area.
I am assuming that you want to visit U.Mass Amherst rather than U.Mass Boston or Lowell.
By car U.Mass Amherst is about 2 hours from Logan airport. UNH is about 1 1/2 hours from Logan, in a different direction. Wheaton is just over an hour from Logan, again in a different direction. You will want to avoid rush hour for all of these.
One option would be to stay a bit west of Boston. This seems to save a bit less than I might have expected. For example staying in Waltham right off route 95 (which we usually call 128 for historical reasons) U.Mass is now about 1 hour 40 minutes, UNH is about 1 1/2 hours, and Wheaton is about 50 minutes.
How I would do this might depend upon how long I wanted to stay in the area. Visiting two schools in a day might be a stretch based on the distances, but is probably doable for most. If you have the time you might want to spend four or five days, visit one school each day, and spend another day visiting Boston. You could visit Boston College on the same day that you visit some sights in Boston.