Buffalo, I have had one delay in about thirty flights over the years.
Last Christmas, I booked AC from Pearson and both flights had multiple delays. I was travelling with my elderly mother, who has many health concerns, and we arrived at the Polynesian at five o'clock in the morning. She was wide awake and bright eyed but really AC! Direct flight, no weather issues. One traveller yelled out that this flight is delayed most weeks so it was all BS, on a regular basis, as his girlfriend takes it all the time. Both flights had the first delay, then another, then another, then another. And so disorganized at the gate on the way home. Chaos.
I don't know why people ever slam Southwest, not here but many avoid booking it, as I have never had one bit of chaos at a gate.
_______________________________________________________________________________________
OP, I travelled on high volume days last Christmas/New Year's, on Air Canada, and my return was $252 - might have been a Thursday return though but still high volume during the holidays, I booked business class on the way down for about $640 - I booked it as a treat for Mom's big trip and more leg room to help her get into the seat. So much for business class when it is the middle of the night!
Anyway, I know I booked late. I had already booked Buffalo and worried about my mom. The $252 might have been as late as a month out. The great business class fare was probably two-three months out.
Best of luck.