Bottom line is 10,000 or more declare with proof. Doesn't matter if it is actual cash or traveler's check.
As Per Canada customs/border website:
Travelling with CAN$10,000 or more
If you have currency or monetary instruments equal to or greater than CAN$10,000 (or the equivalent in a foreign currency) in your possession when arriving in or departing from Canada, you must report this to the CBSA. Monetary instruments include items such as stocks, bonds, bank drafts, cheques, and travellers' cheques.
We remind all travellers that this regulation applies to currency and monetary instruments you have on your person, in your baggage and in your vehicle.
Upon your arrival in Canada with CAN$10,000 or more in your possession, it must be reported on the CBSA Declaration Card (if one was provided to you), or in the verbal declaration made to a border services officer.