I use the antifreeze method; wouldn't try blowing out without someone I trust showing me how. How do you tell when all the water is out? I had a little trouble getting the pump to suck antifreeze out of a jug of antifreeze - had to use a syrup bottle to fill the hose to get it to prime. Finally solved that with a new pump membrane. My water tank is below the pump. I take time to loosen the fitting on the pump so the pipe down to the tank drains. Another approach is to pour the antifreeze into the water tank and pump from there but my pump wouldn't do that.
I'm only 64 and have given up carrying batteries in for the winter and I'm more than a thousand km further north. I disconnect the batteries and check voltages every month. If down from 12.6 even two tenths I put a charger on. Or leave my little maintainer on all the time. Cold doesn't matter unless discharged more than that. It seems batteries store best when fully charged to avoid the dreaded sulphation.
Remove anything mice might like the smell of - the little fellows are good at finding tiny holes.
I park on a bit of a slope so water runs off the flat roof and I use a roof rake to remove snow when it begins to melt.
I have never used a cover but heard it can cause condensation and mold inside, even in walls and ceiling if precautions aren't taken.
This year I changed the oil in the fall instead of spring. The farmers say old oil is a little acidic and can shorten the life of an engine.