Maybe you need to get him a little sweater so he stays warmer while he is outside. You need to get him to stay out long enough to go also walk him around to get it stimultated so to say!!
My only advice is bundle up...sorry....probably not what you were looking for.
Also since you live in Florida like myself I would say no need to worry about potty pads unless you are restricted to an appartment or something that only allows you to use them. If you can train for the yard I say go that route. Our winters are short and sweet so the cold weather is only temporary and usually last only a day or two.
Good luck!