I had a flight SFO-JFK in Mint that was cancelled. They were not able to accommodate me for 36 hours. Plenty of flights on UA that I asked to be put on, but they flat out refused. So I went to the airport (SFO) and did standby, and was able to get out 12 hours later on a JetBlue flight in Mint.

Bottom line, JetBlue does a really really bad job accommodating when flights get cancelled. You have to fight every step of the way to get a flight you want from them.