Hi, Welcome to YT! So are you taking him here to Florida with you? Honestly that sounds better for him and for you.
If it's possible can you get training/obedience classes with him? Most of the time it's the owner who needs training on how to train their dog. Dogs can learn very quickly if trained correctly. If that is financially not possible, watch training DVDs and learn how to properly housebreak him. Leash him to you (on a harness) when he is inside and take him outside on his leash & harness every hour on the hour. When he goes potty outside give him a small treat. Taking him for short walks helps to stimulate their bowels so they are more likely to go potty while taking a walk or running around a yard.
Its going to take a bit of work for sure, esp given his age, but he is trainable.
Good Luck!