Hi from Toronto..
I find it very amusing that you're dreaming of winter hammocking as we suffer through this brutal heat!! Brother, you're not the only one!!!
This forum's a great resource and you'll find ideas and/or feedback about most of your questions.
As for winter camping... The only advice I have is that if you're not sure that your gear will stand up to some extreme cold weather, try to do a test hang in your backyard. You can always retreat inside if things don't work out. I wouldn't field test in the middle of winter unless you have other optinos and/or backup.
I'm sure some of us Ontario hangers will have another winter hang in 2011-2012.
Also, check Shug's extensive YouTube offerings. He covers everything you need to know to get started and then some!!!
If you like canoeing, you might want to consider joining us this fall in Algonquin (see my signature).