I'm not aware of any option in this country (edit: the US) that will handle massive use of streaming video. All of the plans without overage charges have a soft limit where they start throttling you.
In any case, I'm not going to pay a bunch of extra money every month just in case I forget about the WiFi.
In any case, I'm not going to pay a bunch of extra money every month just in case I forget about the WiFi.