I highly recommend you add the Country field and then use visibility rules or javascript to display the correct field and language for the country.
Totally agree with Josh. You cannot legally rely on any inferred data, as it's known to be unreliable. "I didn't know you were in Canada" is not an excuse.
Yes, I agree the inferred location cannot be relied upon. It is set only once (never updated after the first visit) and is often inaccurate (due to VPNs and whatnot). When I reached out to Marketo support they recommended not using it to determine location of individuals, but rather get a ballpark snapshot of where visitors as a whole are coming from.