Don't forget that wide bodies aren't always scheduled for PAX traffic, but often Cargo.

AC had a daily A330 YUL-YHZ-YUL just for Seafood Cargo (to connect to CA flight). 75 people on board. It was as empty on the way there and the FA confirmed it was like that for the season.

Sidebar: $50 upgrade from Y to J. After saving luggage fees, seat assignment and consumption from the lounge, I got the better deal on that one.