You CAN use Google Fi but you need to have a US address to get started. But it works great in Canada. Calls do cost 20 cents per minute while in Canada but the data is the same price at $10USD/GB.

I did the "estimate your bill" for Google Fi. For 6GB of data and unlimited talk and text it's $80USD or $106CAD per month.

Compared to a Telus "Build Your Plan" with unlimited nationwide talk and text, plus 6GB is $90CAD or $67USD.

Looks like it has international support for roaming at the same price though, I wonder if we (Canadians) could just use it anyways...