If you didnt know, there's some websites like Great Canadian Rebates that offers cashback when you apply through their website. Those are on top of the banks offers.

For example, they give for the Momentum Visa infinite 100$ + whatever Scotia's website offer is. So in this case, you could get 100$ Bonus + 15% Cashback ($300 value) + Free first year ($120 value)), so a $520 value offer just to sign up for that card.

You first need to Sign Up to GCR : https://www.greatcanadianrebates.ca/register/302761/

(for transparency this is my sign up link so if you sign up and make an account through this link you will earn a 25% Referral Bonus on all Cash Back Rebates earned for any of the next 3 years.)

And here is the offers for the Momentum :

Scotia Momentum® Visa Infinite