Hi!
I am not an expert on the subject in spite of my surname. Accept my views as only views.
Navratri start and end timings have to be different for different places, especially if longitude/latitude differences are huge.
Whole idea is to measure the movements the moon and the sun in the context of other stars visible with the naked eye. So the moon phase and timings, and even nakshatra in which the moon or the sun rise will vary based on which place on earth you are observing.
To my knowledge, nobody does these calculations specific to their location. everybody follows some panchang and each panchang is prepared to its reference point - typically some city in India.
Following any panchang prepared in the context of some place in India is erroneous for Quebeck.
Secondly, Navratri, like all festivals, has context in Rutu. Entire India has Rutus anchored in the south west monsoon. Navaratri has a linkage to the monsoon coming to an end. That context is totally missing if you are not in a south west monsoon climate. There are linkages to approaching harvest season. It is also beginning of cooler half of the year. If you are in the southern hemisphere, Navaratri and holi has to swap their places.
So, unlike judaeo-Christain concept of fixed dates festivals (for example - December Christmas does not feel the same in australia) being "sanctioned" by some central authority; Hindu festivals are more nuanced and more flexible so far as you keep the basic context and purpose intact.
Regards
Keyur Joshi