If its even near likely, that the temp will drop as much as the water will freeze around your boat you should drain the raw watersystem completely. For the steps and measures you should take, I agree with #2, however with a few things added:
Preferrably, if possible, close the inlet raw valve, loosen the hose and use a bucket with antifreeze mixture and let it wash the system. Also does the the greater good of not having salty water standing still inside the system over winter. Before re-attaching the hose to the raw valve pour some antifreeze in there as well and leave it closed. Same with the other thru hull
valves: Some antifreeze in there. (i.e. the sink and -if you cover the cockpit- the self drains)
, freshwater tanks etc is a good thing to drain however I donīt really think you need any antifreeze in those. One thing ppl tend to forget is the transducer for the depthfinder. If you use a "shoot-thru-hull" ducer, then make sure that the "cup" that houses the transducer has antifreeze in it as itīs prone to break the transducer otherwise. You can also pour a bit of vegetable oil
into the toilet bowl to keep the rubbergaskets in fresh.
After taht you can pretty much relax.
I had a hard time relaxing in the beginning of last winter myself even though I live on the boat. Every little trip I made had me worrying the first few weeks... But then again, we had 50-60 cms of ice and I had a fresh memory of another boat. Left unattended with no winterization done at all.. She went down due to an open valve that cracked.