These days, anyone who travels ought to have a USD bank account and at least one USD credit card. Allows for self-managing currency conversions, including ability to exchange for larger amounts at better rates, buying when CAD is up (relatively). I'd even add rec to open up a combination CAD/USD investment account at a discount broker. Better exchange rate options there. Also, EQ Bank has USD savings account paying 3% which is non-existent elsewhere AFAIK - and a fairly newish option. Easy link to your main bank for online transfers. No need to pay egregious bank fees these days to obtain USD.
With the above in place, piece of cake to engage with discount US agencies for pricing that Canadian agencies cannot (or will not) touch.