One possible itinerary, if you’re flying in/out of BOS:
- DAY ONE: Drive north to UNH (roughly 1:15 in good traffic) and, if you’re so inclined, take a 10am tour. If you do, you’ll wrap up around noon — then grab lunch either in Durham or nearby Dover or Portsmouth (all of which are wonderful). Then head south → west toward Amherst (roughly 2.5 hrs). That puts you in the Pioneer Valley around 4 in the afternoon, which gives you some time to explore and get a bit of a feel for the Amherst/Northampton area.
- DAY TWO: Take the 9:30am tour at UMass, which will keep you on campus until around 11am. Then jump on the Mass Pike and head east toward I-495 and Wheaton, which is 1:45-2hrs driving. They seem to have 1:45pm tours most days, so it seems likely you could be there in time for that late session. You’ll be done around 3pm, at which point you’re maybe 45 minutes (again: in good traffic, which is always an important caveat anytime you’re talking driving near Boston) from BC and the greater Boston area. If you want to do a tour, you’ll have to plan for a third day; otherwise you can just wander the campus on your own and leave Day 3 to your long trip back to OR.
You could also consider flying into/out of MHT (Manchester, NH - 45mins from UNH) and BDL (Hartford, CT - 50mins from UMass), but given that you have to triangulate a third leg to hit Wheaton and possibly BC, I’m not sure that’s going to save you much time or effort logistically.