With that much spending at your disposal, I would suggest you to use them towards the large welcome bonuses of the Amex cards, which all have increased their minimum required spending amounts from $1500 to $5000.

Since the largest welcome bonuses and referral bonuses are with the Membership Rewards (MR) cards, I would target the Business Platinum card for the highest welcome bonus (75K) and referring powers (25K, when used to refer to any of the 4 MR card products: Personal Gold, Biz Gold, Personal Platinum, Business Platinum). You could refer a spouse or yourself (self-referral) and quickly boost up the points totals. It's not difficult to formulate a plan to strategically open 2 or 3 of these Amex Rewards cards and reach nearly 200,000 points, and they can convert 1:1 to Aeroplan if that's your preference.

What's not so easy for the average person is finding ways to meet the minimum spending requirements, since Amex has increased them significantly in the past year or so. But with your ability to funnel say just $10K-$15K of your large annual spend on a few of these cards cards you would easily accrue much more points and likely a lot more quickly than you would by flying or devoting all of your spending onto one single card.

You can get some ideas at the American Express Canada application and reward strategies (2017) thread.
See the link in my signature for an example card signup plan.
See also the Amex Canada SPG thread.
And one more, the MilesBuzz Canada thread, for other CC product ideas for points.

After meeting the minimum spending requirements you would still have a large annual amount that you would then be able to spend on whichever card points program that you fancy, but generally speaking the SPG Amex card has the best average cpp value.

For your reference, Amex Canada limits you to 2 CREDIT card products (eg, the SPG, SimplyCash cards) but you can open as many CHARGE cards (MR and Aeroplan Plus) cards as your credit strength can bear. Usually just one of each specific card product though, such as 1 Personal Gold MR card, 1 Business Platinum MR card, 1 Aeroplan Plus Platinum card.