Outland applications are processed through the visa office that serves the applicant’s country of origin, or where they have been lawfully admitted for at least one year.
Since the overwhelming majority of U.S. applications are process IN Canada (Mississauga first, then sent to Ottawa), I suppose the interview that you're convinced you will have, will be in Ottawa.
Trust us when we say that you're worrying needlessly...honestly. There have been so many U.S. applicants that chose the Inland path and regretted it in the end.