I would definitely advise you to get as many of the exams completed before you fly out to Florida.
I was at OFT for the whole of June last year and did 6 of the 7 exams in the first 2 weeks (starting from scratch, no study in the UK first).
Although the material is not hard to understand, it was mentally exhausting and learning it all and it certainly affected my capacity to soak up everything I needed to on the actual flying side of things. In addition to this, intensive studying at the school itself isn't very easy, there are always distractions, so you'll need to do most of the study back at the apartment/hotel, but, on the other hand, being away from the school means that you may miss opportunities to fly (if you're on a 28 day course you'll need to grab *any* opportunity that comes your way, you'll need them!).
Also, as you're going to OFT, be aware that they may tell you that accomodation is included in the price, but when they get busy you may find yourself, at the last moment when you're already committed, being told you're paying for your own hotel room.
Anyway good luck !!!