I can't find any record of the Downtown Athletic Club announcing "finalists" for the annual Heisman Memorial Trophy before 2004, when the TV show started to cover the announcement live as a Major Life-Changing Immortality Event On ESPN Brought To You By Nissan And Wendy's. Before that, there's just a record of the winner and the runner-up, so before 2004, I can only find an effective record of two "finalists" per year.

With that in mind:

Since 1966, when Steve Spurrier was the first player from any university in the state of Florida to be a "finalist" for the trophy, nine players from universities in Florida have been "finalists."

They've won seven of those times, and come in second twice. In other words, when a Florida-based player is a finalist, he wins 77% of the time.

For contrast, there have been 15 Oklahoma-based players named as "finalists" in the trophy's history. Six of them have won, for a 40% winning ratio.

If someone who plays his home games in Florida is named a finalist, your smart money is on him to win.

Update: I think I remember that the Heisman presentation was on TV before 2002, and that multiple finalists were named before that—I just can't find any record of it. It would only change the statistics if someone who played home games in Florida was a finalist but didn't win the trophy (or come in second). If you have a source for a list of finalists, let me know.