Sorry for the late response to timnboston but I've been away from computer.

Jet Blue out of Boston has direct flights on weekends to SXM. They had suspended them due to Irma and airport problems in SXM . Last March we had to go thru NY and we'd waited so long that couldn't get a flight that would connect so we drove to JFK the day before. Everything worked out. Surprised that it was a good drive.