They're covered by Credit Union Deposit Guarantee Corporation of Manitoba, which insures 100% of eligible deposits.
Bear in mind, though, that deposit insurance is only as good as the insurer. If a major bank or credit union were to fail, the overall economy would have to be so bad that it would spawn a whole slew of failures and eventually, the deposit insurance funds would be overrun – forcing the government to borrow copious amounts of money to cover deposits or do an about-face and stop guaranteeing deposits.
Your best bet is to park your money with an institution that is financially solid, of the highest calibre and globally linked. In short, one that is "too big to fail".
Cheers,
Doug