Thanks for the confirmations!
Based on slow London busses, train is my first instinct, but now I wonder if the return trip should be the same, as we need to be at EWR at 6:30 am Tuesday. The itinerary planner shows us needing to leave Penn Station at 5:35 am (long transfer time), so might it not be faster to take a cab that morning?
It would be faster to take car service. It's cheaper than a cab.