Ok few examples of such agencies that work Canada wide: Adecco, Hays, Kelly Services... Some of them have just manual work, but others have some temporary office openings as well. Just use google to identify them. Sticking with Montreal might not be a good idea for you. So maybe it is time to switch to a different province. Also if you go for industrial openings, those are not that much in Toronto itself. It is more like GTA region or more south (Mississauga, Waterloo Kitchener, Cambridge, Windsor, Guelph).