My wife and I plan on flying from Quebec City to San Francisco on a Saturday in late September. We'd be traveling business class, with just carry-on luggage, and have U.S. Global Entry/Known Traveler. A few questions:

1. One option is connecting through YYZ early morning, with a 1:24 period between YYZ arrival and departure. Does this leave enough time for a fairly safe connection?
2. The other quickest options are through YYZ or YUL late afternoon/early evening, both connections about two hours. I assume these are fairly safe in and of themselves, but an wondering whether those times of day we'd be more likely to encounter delays out of Quebec, compared to the early morning flight.
3. Most generally, any reasons - re connections or otherwise - to prefer going through YYZ or YUL?

Thanks for any advice!