Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Canada to Normandy as you normally would.
Due to the rapidly changing circumstances due to COVID-19, airlines like Air France flying from Canada to Normandy have implemented new flexible change policies.
Yes, there are multiple flights from Canada to Normandy for under C$ 1,000. The cheapest flight booked recently is on Air France for just C$ 1,000, but on average you can expect to pay C$ 1,159.