I am not following your story...
Were you bumped or delayed? If bumped, why would it be for 4 days.... there are near-hourly flights between YYZ and YUL.
Where was it -28? Weather for YYZ that day shows high of -6..why did you have to walk outside to find a hotel? You can book from the airport and use their shuttle.
If you are looking for help, maybe put the emotion aside and explain clearly what happened and what advice you are seeking.