大手都市銀行はトピ主さんの理解で合っていると思います。大手都市銀行はフェデラルが、クレジットユニオンは州が管轄です。BC州のクレジットユニオンの場合、CUDIC(Credit Union Deposit Insurance Corporation)が金額にかかわらず全額保障しています。http://www.cudicbc.ca/
CDIC insures deposits in Guaranteed Investment Certificates (GICs) and other deposits with an original date to maturity of 5 years or less held in Canadian dollars at a CDIC member. CDIC does NOT insure term deposits (including GICs) with an original date to maturity of more than 5 years.