Last few times I've tried this, going through YYZ, I wasn't allowed. I checked in at Jazz stations though (YXE, YQR, YPR), where they might not be able to, or might not be allowed to do any manual override of what usually is a domestic 4 hour connection bag hold limit. Even during the daytime, I wasn't allowed (ie: a 6 hour connection at YYZ!).


So YMMV.