In fact Justin Trudeau considered invoking it for the first time since the replacement in the COVID situation.
[edit] Between that and the Notwithstanding Clause [1] there's a lot of latitude here.
[1] https://en.wikipedia.org/wiki/Section_33_of_the_Canadian_Cha...
> 9 (1) Nothing in a declaration of a public welfare emergency or in any order or regulation made pursuant thereto shall be construed or applied so as to derogate from, or to authorize the derogation from, the control or direction of the government of a province or a municipality over any police force over which it normally has control or direction.
https://laws-lois.justice.gc.ca/eng/acts/E-4.5/page-1.html#h...
[Provinces can request military help, but that's unrelated to either the emergencies act or the now repealed war measures act]