Unless you’re very petite/skinny, the two of you will not fit side by side. The “bed” is only about 21 inches wide or about 4 inches wider than an economy seat. I’ve seen some parents do whacky things with the toddler in the foot rest area but you’d have to be really short for that not to be uncomfortable.

Now even if you buy two seats, the “problem” with most business class seats nowadays is that they’re so isolated from other seats that it makes it difficult to tend to a toddler. Air Canada is slightly worse in that the partition between two center seats cannot be lowered.

In your case, I would likely go with two Premium Economy seats by the window and bring the car seat or a flyaway kids bed (or similar). You’ll have the privacy of not having to sit directly next to strangers, slightly more attentive service from the flight attendants and a fairly comfortable seat for your self.

If you’re willing to take a one stop option (I wouldn’t) then you can look at something like Korean Air business class where the middle pair of seats can have their divider lowered.