1. You should be able to use the
CATSA Trusted Traveller line by showing your Global Entry card. (Unlike TSA Pre, the CATSA TT line doesn't depend on airlines showing it on your boarding pass.)
2. You'll have to enter Canada the old-fashioned way; only NEXUS/Canpass will speed that up, not Global Entry. If you were flying on to the US you would be able to use Global Entry to get through US preclearance, but you're driving so no.