Be sure to check traffic reports. If you're in SI and they close part of the VZ you'll have a problem. Plan "B" would be to go via the Holland Tunnel through Brooklyn & Queens.

The last time I took a flight from JFK (many years ago - my SO had insisted on a nonstop vs. 1 stop from EWR at the time) we heard on the radio that the VZ was closed due to a major accident and then went via the Holland Tunnel. Made it to JFK just on time. Boarded the flight. The Captain came on to announce that we'd be delayed at least an hour if not more as the copilot was stuck in traffic in SI.