Hi Rosa and welcome to Permies!
I think J is talking about Rob & Michelle Avis in Calgary. They have a bunch of good resources at their website (
http://vergepermaculture.ca).
I have spent a lot of time reading about permaculture. And I feel confident that it could be done even in zone 2, maybe even zone 1. The beautiful thing about permaculture is that it often succeeds where other methods fall short.
I also live in zone 3 and I have many plans in my head to begin implementing permaculture on my homestead in the next couple of years. Based on what I hear from Albertans I'd say we have it colder here but your weather is weirder. So far I prefer colder.
Anyways, all this is to say that yes, I 100% believe you can do it where you live!
Another excellent example of cold climate work is Sepp Holzer's work in the alps. I don't know what zone his property was... but it's probably a couple of zones warmer now after he fiddled with it. :)