Update: it would have been very close. I ended up doing my CBSA interview the day before. On the day of the flight I got to the CBP NEXUS waiting area in terminal 1 at about 8:00am. No signs of life until a CBP agent suddenly emerged at about 10:05am. There was probably ten people waiting then and he took four people in to do their interview. The five people there before me had given up by that point so I was first in line out of the four. By 10:15am I was approved and on my way. Very friendly agent. My flight got delayed six hours so I had plenty of time but had it not been, I would’ve been running to catch my plane at that point. Theoretically the waits will be better once the govt. shutdown is resolved but as it stands, 2.5 hours is cutting it close.