You can vote in it as many times as you want if you just "delete cookies" between casting each ballot. I did 7 times before realizing that it was beneath my dignity.
Honestly? Why would CBC want to run such an easily manipulated survey? Sure, you claim you did a poll and its cheap, but you get what you pay for.
Easier to see why, as has happened here, a gang of young Tories might want to spend the day drumming up fake votes. CBC will, if they announce the results at all, include some caveat such as "this is not a scientific survey". Writers from other media outlets may not be so scrupulous, and it will get printed and broadcast as though it were actually news.