Two years ago I needed period fabric for historic costumes - linen, wool, etc. I ended up ordering from the States with great results! Since then, I have seen more and more specialty on- line sites. A few months ago, I was sourcing diaper supplies. Between the small yarn dye-ing businesses and fabric suppliers, it appears there are many DIYers out there!
Thought some of you might find this link useful:
http://finishedgarment.ca/canadian-online-quilting-fabric-stores/
"The big list of online Canadian fabric, patterns and notions stores"
And, of course, not Canadian based, but a wonderful source of fine heirloom sewing supplies, marthapullen.com