I wouldn't say it is impossible but it will most likely be very, very tight as you are on separate tickets. Having Nexus would help immensely (GE will only get you faster access through U.S. pre-clearance via the kiosks, Nexus will give you potentially faster entry into Canada and definitely faster clearance through U.S preclearance security and immigration. You may also have to deal with cruise pax traffic which would impede rechecking your bags (if AC will not thru-check them). Hope you have suitable *A status.
If AC will check bags through, there is an Intl=>U.S. connection facility that shortens time required but after going through the GE or APC kiosks, you have to wait for your bags.