I'll have to read up on the antifreeze. I know you dilute automotive antifreeze to a 50/50 mix but most of that stuff is ethalene glycol (sp?) and is very toxic. We've lived up in Alaska for over twenty years now and have used the pink stuff in several campers/trailers/RV's we've owned over the years and we've always used it full strength, but maybe we've been doing it wrong all this time. I never thought about old oil wintering over in the enging as being bad, I change it out in the Spring but I guess if it's corrosive, I might as well change it in the fall and get a jump on my Spring chores. Do they put ethanol in diesel fuel?
Normally (not this year) we keep her in the water and hooked up to shore power with a trickle charge going to keep the batteries up. When we go down to shovel the snow off of her (once a month or so) we fire up the espar heater and stay aboard over the weekend. We use the propane stove to heat coffee and such, so I don't want to take the tank off.
I forgot to mention, we do cover the winches, remove the steering wheel, and cover the binicle.