We'll be in WDW in February for 8 days and that has crossed my mind as well. The only issue with that is even if you have someone check your mail every day, you have 1 day to complete the affidavit and send it back. So if there's a notification from Fedex that they tried to reach you, your neighbor or whomever else can't go pick up the letter from Fedex. Or let's say they deliver the letter to your home without actually making sure you're home. How are you supposed to get the affidavit to FL, find a notary and Fedex it back all within one day?
I think I would rather not know until I came back that I would have been a winner, you'll end up spoiling the rest of your vacation knowing you could've won, but because of logistics and timing, you missed out.