Hello @Adam24412,
You will pay $8/day when roaming in the US and $12/day when roaming to any international destinations. You pay for the first 15 days per destination then the rest of the days is on Fido and that's witing your billing cycle.
You use your phone just like if you would if you were in Canada and if you go over your data limit then you will be charged for the overage and the amount depends on the overage fee on your plan.
You can learn more about the Fido Roam here.
