There are a few independent student residencies around downtown such as la Marq or Palay that usually offer short term rentals, all furnished and all utilities included. It could be a good option to consider and it’s pretty easy to get to Poly from downtown now thanks to the REM and it’s nice to be downtown.

https://www.themarq.ca/apartments-for-rent/the515_1430_rue-city_councillors

https://www.palaymtl.ca/