If your worried
 

If your worried just run a long extension cord out to the boat and hook up a 100 watt light bulb in the engine compartment and close it. One little ole light bulb and your compartment will stay above freezing. Ed :drink:

Here in Texas it really doesn't get cold enough for long enough to winterize. When I had a boat I bought two of those flameless propane camp heaters. My boat was stored two miles from me so I would go and fire them up when the forecast was below 30* or so...

That is great advice. We did this all the time in Minnesota to extend the boat season in the fall/winter.