Hi,
I called them and they gave me the appointment really quick, since I'm in Ottawa they told me we can do the appointment at 10am and by 2pm they can get my travel document ready. So I spent the whole day there waiting for my travel document. An advise: when I arrived there, they want me to pay a pre-pay envelope in Canada Post to sent my travel document back, but I complained about since they told me that I can wait, so I didn't accept it and I say that I was going to wait. At the end, everything was normal and I returned to Ottawa in the afternoon with no issues.
So keep that in mind when you are applying.