later in the summer florida gets regular afternoon thunderstorms (big ones which you will want to avoid at all costs). the school should plan the day about these storms which arrive nearly every day in july and august, between 3 and 6 pm.
so if you can only go in the summer, the earlier the better.
as for the study, as you have plenty of time, get the exams and your CAA medical done before you go, then you only have to worry about how to fly the aircraft, and you might get some free time to take in the local area and floridas great beaches.
if, like me you hate to study alone, it may be worth going to a 1 to 1 trainer, you will see ads in flyer, pilot etc. i can recommend david deacon at lynair. its not the cheapest way to pass ground exams, but in the whole cost of learning to fly its no big deal.
good luck !!