DUCA Financial (Ontario Credit Union) - 3% promo rate till May 30, 2020 (Dead for new funds)
Before anyone asks, they are not covered by CDIC since they are a credit unit but they have DICO insurance which is what covers Credit Unions in Ontario. $250,000 limit
EDIT - I read over on the other RFD thread about DUCA (the ongoing one) that you can actually transfer funds over from previous PROMO to chequing or savings account and then get them to setup the promo for you at the branch or in person and then transfer it over to the new promo account. Best to verify on the phone.
April 1, 2020 Update - from Inspectah post near end of thread, sounds like the promo is done for new monies:
1. They will no longer transfer new deposits into the Winter Promo Park account
2. Any existing balance in the Winter Promo Park account will continue to earn 3% interest until June 30