They used to have a 5gig plan for Canada. On my MiFi, I paid roughly $110 a month and could use my device in the US. Canada, and I think Mexico. The price was actually somewhat cheaper because you could flip it on and off as needed. Then one day, it was gone without notice.

What about an unlocked MiFi style device with a Canadian prepaid SIM. You can get the Zoom Router for apx. $150 and use it globally. XCom Global rents Canadian MiFis.

http://www.xcomglobal.com/coverage/canada.html

iPhoneTrip has a 1gig sim only plan for $7.95 a day.