I would pull all the plugs and hoses to get the water out and perhaps put a heater or trouble light under the engine cover. I don't think you need to go the antifreeze route if your temps are only going down to the mid to upper 20's. What are the high temps you are looking at?
CUSTOM WHEEL & TIRE PACKAGES
$125 LED LIGHT PACKAGE - FREE SHIPPING
REBUILDING HOLLEY MARINE CARBURETORS - $249 DELIVERED
Email - firstname.lastname@example.org