Go to the SkyTeam website and look for the link to TIMATIC. Enter your details and you will see the regulations that *most* airline agents see when they check the requirements. However, DL "has its own version of TIMATIC" and can be very stubborn about such things. Therefore, you need as much ammunition as possible. Print the TIMATIC result and also what the State Department website says (assuming that you're a USA citizen), although the USA State Department has absolutely no authority regarding your admissibility to a foreign country (including Canada) and can be seriously out of date or inaccurate. You should also go to one or more Canadian consulate websites (for the LA area and various other regions in the USA) to check the rules and print the results to show to DL agents if needed.

However, if you have time, why not renew the passport now?