We are also flying into FTL the day before our cruise in December, in order to use miles. We are staying near the FTL airport at a hotel that has a free shuttle. We are then using SAS TRANSPORT SERVICES (954-600-0240) (
http://ridesas.com/index.html) to get from the hotel in FTL to the port in Miami. They will also pick us up after the cruise & take us back to the FTL airport. They charge $15 per person, each way, plus a tip, so for 2 of us it's $30 round trip versus $60 for Carnival's transfers.