Hi songsort! (Just my point of view) please see below the calculation:
800,000 CAD= 615000 USD @ 1USD 1.33( as on 10/04/2016)
800,000 CAD refund which you get after 5-6 years will be equivalent to =500,000 USD
( let say after 5 year in 2021 / 1USD=1.6.CAD) in that case you will loose 115,000...