We did the BBC tour with both of our kids and enjoyed staying Freeport, specifically the Hilton Garden Inn right in downtown Freeport so everything is walkable. Both times we did Colby on one day, and Bates and Bowdoin together on the same day which was easy enough to do. (Full disclosure, D graduated from Bowdoin and S is a sophomore at Bates, but they both liked Colby as well.)
We have visited at different times during the year, and even in the dead of winter there are a lot of beautiful areas on the coast…if you are okay with bundling up!