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 CARBS - $249 DELIVERED
REBUILT COMPLETE MARINE HOLLEY 4160 CARBS
FOR 302, 351 & 454 STARTING AT $425 DELIVERED
Email - email@example.com