If you get deferred do not feel as though it is over and done. Far from it. You still have a great shot. The best thing you can do to maximize your chances is to submit your mid-year grades, and write a letter to your AO stating your continued interest in Miami. Definitely state if it is your number 1 choice, and that you would attend if selected. I would also give a few reasons why you love to go to school at Miami. And mailing the letter to your admissions officer rather than email is also a nice touch.