Certainly, having Nexus and not checking bags would help. The preclearance area shouldn't be too busy at that time of day. As others have said, lineups can vary widely. I usually look at the flight schedules to gauge the expected passenger volume. If you put the following into ITA, you'll get all the transborder flights from YOW:
NYC;WAS;BOS;DTW;ORD;PHL;DEN

There are both UA & AC flights to IAD at 2:35 (2 separate flights, not a codeshare), NW to DTW at 2:50 and CO to EWR at 3:30. All are CRJ/ERJ. Considering that there would be hardly any connecting passengers and the check-in/baggage drop deadline is 60 minutes, I think that by 2:00, most IAD and DTW people would be through and the EWR rush not yet at max.

It's tight and definitely a risk (particularly if the YYG flight is at all late), but I think there's a fighting chance.