you will not need iodide. I used to live 10 km near a nuclear power plant for 5 years and the government handed them out for free but we never needed them. Basically you will only need 1300 mg of it before your body can't take anymore and that is 10 pills. The prescription that we had was 1 tablet a day with a dosage of 130 mg which means it gives you a 10 day protection only and anything after that you are on your own. Please don't go out and stock up on these and god forbid please don't take them. I'm sure the canadian government will hand them out IF its needed, but you won't have to buy them yourself right now. Just some FYI on radiation fallouts and iodide.
Edit: if that doesn't convince you eat lots of seaweed, its rich in KI.