The Dino museum I mentioned is the National in DC. Let me think a minute.... Gonna say you'll need a full day for Hershey, full day for the Dino museum. Two days travel from Boston? I've dreamed of seeing the two museums since right before Covid hit. The National reopened after being closed for years for remodel right before Covid and then closed from Covid... So did the Tank museum. Both are roaring again though I think. By the way, I have just about matching grandsons! 3 and 5.