I happen to apply from Montreal BLS and my timeline is below. Just go to the BLS with the correct documents and i think it was incredibly fast. I just wanted to give a try before receiving the Canadian passport and i have got the surrender certificate in hand today and yet to get the Canadian passport.
Timeline:
18/11: Submission for Surrender Certificate
21/11: Checked status in BLS website,, read as "In transit to High Commission Ottawa"
22/11: Status in BLS website, read as "Under process in High Commission Ottawaa"
23/11: Got to know from this site, that we can check the ARN status in the high commission page where we created the Application. Checked here and the status read as "Surrender Certificate has been printed"
24/11: Same status stayed in BLS website and the High Commission website
25/11: Check the status in BLS and it read as "Ready for Collection" though the high commission website still showed "Surrender Certificate has been printed"
25/11: Went to BLS because i did opted for a pickup and i have my surrender certificate and cancelled passport.
I am posting this here, only to let you know how to track and the status that shows in each site which is not very clear anywhere. I think, the timeline might depend on the area and the volume of passports they receive. I hope everyone is working hard behind the scenes, otherwise nothing will move.