Rent a car, spend the night in Ft. Lauderdale near the airport, and then drive yourself to Miami in the late morning.

I agree with Doug.... I would get some sleep, eat some breakfast, and then head to Miami the next morning right after rush hour traffic.

You've tagged several cruise lines - you haven't made the cruise reservation yet? Check with the cruise line what's the latest time of boarding, if the cruise starts at 4, you must be there no later than 3 or maybe earlier.

You can board the ship early, maybe from 11 am, have lunch in the buffet, walk around the ship, learn the lay-out. There may be "welcome aboard" activities. Your cabin will be ready at 1 or 2 pm.

So have a good night sleep in the aiport hotel, have breakfast, and from there drive, shuttle, or taxi to the ship.

Why rent a car? Why not grab a cab instead?

The fare from the Ft. Lauderdale airport to the cruise docks is about $80. If you take a taxi to a closer hotel, you might be able to just take the hotel shuttle to the port and save a bit more...

The OP is arriving at midnight. A taxi or shuttle service might be appropriate if the OP waits until the next day, but it's much cheaper to rent a car for the one-way trip in almost all cases.

I believe Thrifty and Alamo even Avis have rental locations at the port of Miami. A hotel stay near FLL or North Miami Beach ($60-80 per night) with a one way car rental from FLL is probably your best option especially since you are arriving close to midnight.

North Miami Beach can be a decent place to spend an early morning or afternoon before your cruise. Nice beach area, quaint hotels, restaurants and walking areas.

If you are arriving at Ft Lauderdale and need to get to Miami, check with the cruise Line who may offer a free transfer to the port.

We cruised with HAL from Ft Lauderdale in November and our transfer from MIA airport to Ft Lauderdale was included in the package. We had booked an overnight in Ft Lauderdale with them and it covered MIA to Ft Lauderdale hotel and then hotel to ship the following day.

The cost was about the same for the night in Ft Lauderdale incl transfers as a straight transfer from the airport and the following days transfer.

Cruise is booked with Carnival, we are doing a back to back cruise with Glory than Valor. We end up booking a hotel with Crowne Plaza, they have a 24 hour shuttle that will pick us up when we call. We are now looking to use www.ridesas.com
has anyone used them? Do they pick up at hotel or do we need to go back to the airport.