If you're not running the boat once a month, I hear you need to fog the cylinders, and maybe some StaBil in the fuel.
I do my annual service in the fall, and last winter ran the boat a little less than once a month. Longest stretch may have been two months.
The best answer is not to fog, etc., but to take the boat out once a month. No worries about freezing, or block draining or anything our northern brethren have to deal with.