My mom went to her Whirlpool interview over the weekend. Was easy in and out, no more than 15 mins. They had a list of of schedule interviews for day in and taking people early. She went in 15 mins early and came out just before her scheduled interview slot. people , did the fingerprints and scans, then US interview then Canadian.
US asked standard why you want it and that was pretty much it. More time explaining Global Entry, KTN, bridges, lanes etc..

Really good hope Canadian side opens soon.