Never grown Poblanos, but the NM varieties that I grow really like a lot of sun, and while they can take a few cold shocks, they will likely die if there is a late spring or early fall frost. They won't produce very much during the intense heat of June here, but once it cools down a few degrees, they'll go nuts. I had some this year that started putting chiles out before it got really hot, then they kind of chilled out, and now they're booming. I should have my first real harvest in one to three weeks. I am guessing that Alberta doesn't have quite the growing season that we do, and you may have to worry about colder temperatures just based on the fact that it's in Canada and my state borders with Mexico. From the first day of spring to the first day of fall, you have more than enough sunlight, but the rest should depend on your average first/last frosts. I'm guessing that in your climate, it'd be good to start them indoors around April 1-15 and transplant a couple of weeks after your average last frost. Unless you have a decent sized greenhouse, that is.
As for getting seeds, you should be able to order them online. If you want some NM varieties (not Pobolano,) I can point out some websites for you.