FYI for anyone going to the US, YYC will turn you away from US Customs if you are there less than 2 hours prior to your flight time.
https://calgaryherald.com/travel/cal...gh-u-s-customs
I'm not sure now this will work for morning flights. I've had early morning flights that leave at like 6:30 am and been there at 4:30 am ish and the security area wasn't even opened till about an hour before the flight time. Not sure if that has changed since the last time I had an early flight. Once I was the very first person through security and customs in the morning and the very first person into the airport terminal. Felt very eery being in an empty terminal, lol.