I think driving would be a total crap shoot, though it might be possible. It is a Tuesday. US Helicopter is dead. I would say that the train would be a better option as far as relibility is concerned. There is a 4:27 NJ Transit train (possible if you left E34 & the river at 4) that arrives EWR Station at 4:55. Then there is the matter of taking the AirTrain, tacking on another 10-15 minutes depending on which terminal you fly out of. Do you think 1:20 (in the best of circumstances) is enough time? I know everyone values their time differently, so I can't say.

The train prior to the 4:27 is 4:17 and 3:46 before that. Anything later than 4:27, (5:03 is next) becomes sketchy.

I thought I remembered the trains running to EWR more frequently, so if I am missing something from the NJ Transit schedule, someone please correct me.