Hi Mike-
We got all of ours from Heritage Seedlings (as well as a few private and randomly purchased commercial trees to help with diversification), but they are the wholesaler to wholesalers. The only online source I know of is Coldwater Creek Nursery. IDK if they ship to CAN or not.
If you can find some, they should do very well; the tallest and biggest dawn redwoods in the world are just a couple hundred miles south in Corvallis, OR. I was also amazed to see a huge honking giant sequoia in Vancouver. It had to be fifteen feet in diameter.
Thanks to Dearly Depotted for seeing this and emailing me; I would have missed it for quite some time. You can PM me or email directly to the contact email on the site:
dawnredwoods@cs.com for the fastest response.
Doug