It's up to the airline who made you late to re-accomodate you, which in this case would be Air Canada. Expect more sympathy if the delay is in their control (as opposed to weather related). However, be aware that it will be up to you to deal with AC and not with NH to get the issue resolved I could see them booking you on the CA flight if they did it. I can see them asking you to overnight if they didn't do it. But in case of IRROPS anything can happen