Likely so, via yet another undocumented policy. (No charge to SDC to an earlier flight at a connection point). And the first might be. But depending upon G space two days before a holiday, and moving forward in time to boot, this is a tough ask. (All things being equal, it's easier to move to an earlier flight than a later one, because you can be among the first to try to move to a flight at precisely T-24. However, all things are not equal in this case: trying to move from the Tuesday before Thanksgiving to the Wednesday before Thanksgiving is unlikely to work).

I'd also consider comparing it to the cost of upgrading SFO-YYZ. While it's not a flat-bed, and daytime might still be preferable, red-eyes in F are much less miserable than red-eyes in Y -- unless you can get an entire row.