I found observation of I. edgeworthii from Montreal https://www.inaturalist.org/observations/312751574, but I can't contact observer.

This is very interesting observation, possibly first in North America.

Impatiens edgeworthii comes from Western Himalaya and in last two decades or so is naturalizing in some European countries.

Can anybody working in Montreal help me in collecting more information?

Most important things are: status of locality (plant in cultivation/escaped/naturalized); population abundance; habitat description; history of introduction.

Wojciech Adamowski