You might simply want to talk to your carrier. Unlocking the 8830, at least in the versions used in the States, has most often been something that the carrier opens up -- usually quite readily -- for you. Your experience in our neighbor to the north might be different.
Note that when using a foreign SIM you will also have a different phone number as well as no access to data.
Ask Bell if they have any travel packs that can be added to your account? They did something like that for me when I was travelling to the US in May. I know that Rogers definitely does as I was inquiring about them for one of your guys travelling to Spain next month.
I used my 8830 all over France, and Sprint didn't sting me too hard for roaming & data (it's a business line, and a US$300 phone bill for a month of European service isn't a huge deal).
BUT- If you don't want to have that kind of surprise when you get home, get a local SIM. Go to Continent, Darty, Auchan or similar when you get there, and sign up for local service. You'll lose your North American phone number, and you can't get a data plan without signing up for a 1 year contract, but at least you'll have reasonably priced phone service.