For our cruise this past January, DD17 and I flew into Fort Lauderdale the day before, rented a car, and stayed at a Hampton Inn in Coral Gables. Shopping and restaurants within walking distance. Morning of, we drove (not far) to Fairchild Botanic Gardens and spent 3 hours there - it was lovely! One of the highlights of our vacation! Drove the rental car to MIA, returned it, and took the shuttle to the port. Arrived at the port about 2 pm, no lines, basically walked onto the Wonder. Easiest embarkation ever!
If we ever leave from Miami again, I would try to do exactly the same again!!