Our flight leaves at that same time and we always get from VG no problem. Agree with George, don't get on any later than 10AM. We seem to depart on Sundays the last few trips and so we have done the 6AM to Trellis and then the 7:30 to STT. Honestly, if you don't mind getting up that early, it is a really easy time to do the trip stress free. You know you have back up options that way, plus the ferries and customs are rarely crowded that early. Last month we were through customs in about 10 minutes. It was great! We always like having a nice big breakfast at Glady's before our flight.