Thanks everyone for the tips. At this point I think I'm better off paying for a commuter flight to get to San Juan in time to make the connection to go SJU -> ATL -> BDL. Ground transportation from Worchester or Providence to Hartford at Midnight is NOT the way to end a vacation.

I was shocked at the limited options but sounds like that's a correct interpretation of Delta's liability. I (apparently mistakenly) thought they could do better.