It may bre true that "literally no one cares," but to protect yourself I would recommend taking to your department, given the wording in the CGSM agreement:
Change of Program of Study, Supervisor, Research Project or Degree
A notification of change to a program of study, supervisor, research project or degree must be sent to the Faculty of Graduate Studies (or its equivalent).
If the research area of the project or program of study is modified, the award holder must submit to the Faculty of Graduate Studies (or its equivalent) a one-page outline of the new proposed research, along with any other documentation required by the host institution. The subject matter of the research must be aligned with the mandate of the original funding agency. Additional information on subject matter eligibility is available on Science.gc.ca. If the research project or program of study is modified to an extent that it would no longer be supported by the original funding agency, the award will be cancelled at the discretion of the host institution. Agencies reserve the right to review the one-page outline to ensure that eligibility guidelines are met.
From: http://www.nserc-crsng.gc.ca/Students-Etudiants/Guides-Guides/CGSMAward-BESCMaward_eng.asp