So given that AC only flies the A220 in North America, range isn't a huge factor. What is a factor is how will the additional capacity of a 225 stretch fit into AC's fleet and will they be able to fill those additional seats at a profit.

According to ChatGPT Air Canada's top ten airports in terms of number of flights are YYZ, YUL, YVR, YYC, YOW, LGA, EWR, BOS, JFK, and LHR. All of these airport (with the exception of LHR) would benefit from the increased capacity of a 225