I have changed between NY-area airports a few times, once due to being sent home midway through a trip that turned into a "trip in vain", most of the other times due to weather issues and once just because I didn't want to trek to LGA and was able to switch to a flight out of EWR, but I wouldn't count on it absent IRROPS.

Especially an airport 2 hours away? You could call the Preferred desk or show up at the other airport and beg for mercy, but I'd give you about a 1% chance of success.