You can try taking the NJT Morristown Line to Denville and then catching a cab from there.
Here's the schedule:
http://www.njtransit.com/pdf/rail/R0040.pdf
The last train leaves NY Penn Station at 1:19AM.
There's also a Montclair-Bontoon Line train that leaves Hoboken at 1:17AM. You can take it to Bay Street and then take a cab from there.
Here's the schedule:
http://www.njtransit.com/pdf/rail/R0030.pdf
It's not much, but it buys you another hour or so.
Also, there's a taxi stand at Newark Penn Station, so it'll be cheaper than taking a cab directly to Manhattan (the NJT Northeast Corridor Line runs until about 1:50AM I believe, and the PATH runs 24/7)