For a quilt that size I would take it to a laundromat and use one of their large commercial machines. You want to wash it with Color Catchers (called something else in Canada, I'm sure someone will chime in with the correct name). The color catchers grab the die that's shed into the water, but they need a LOT of water to work. Probably more than a top loader + king quilt can provide and NEVER use them in a front loader.
I use cold water and gentle cycle. I dry mine in a dryer till almost dry, then finish on a line, but in this weather, you can just lay it on a bed & turn it occasionally.
Here's a link to a discussion with some Canadian sources:
http://www.quiltingboard.com/main-f1...s-t207926.html