Based on your home location, I see two choices and two reasons for them.
First, if you were to travel to Miami on embarkation day (since your are so close) that would be the best choice - no overnight stay required the night before.
If that is not the case for you, because you just want to be there the day before, I would prefer leaving from Panama. It's the more difficult journey and requires flying the day before anyway.
Then, on your return, you have the quick trip home from Miami.
I chose something like that last January - sailed from LA to Miami (the reverse was available).
The flight home was 1/2 the time, plus, we were not 3 time zones out from home. Got home in the afternoon eastern time instead of hours later.