When do you leave? You could just pay someone in Canada to buy some prepaid cards for you and mail them to you, or give you the voucher numbers...

I grew up ten miles from the Canadian border on the US side. I've never had a problem buying a prepaid SIM in Canada. I've had a harder time finding a SIM only deal.

Stu

PS: I don't know our personal needs, but what about just using Skype and hotel wifi?