I used my Chase Amazon in NY and PA on the long weekend and had zero issues with it. Exchange rate was ~1.27 whereas getting cash from a CDN bank was ~1.29 - not that much difference.
$300 cash advance + $5 fee = $305. $300 cash in pocket + $6 with 2¢ exchange premium = $306.
The card is much more convenient at the gas stations so you don't have to go in and prepay.
I also used that card in Italy for a cash advance and then went into my banking app and paid it that same day - did not get an interest charge.