I also live in Ontario brother not all that far from you , and I can tell you that you instead of pruning your plant right now , you should be getting it ready for it last bit of stretch and training while you still can (before the stalks really harden up) I would use LST method of training at this point to optimise the lighting your plant will receive by spreading it out pruning will cause alot of uneeded stress and can cause your plant to slow down in flower development . LST will help boost yield and flower structure in your outdoor grow and prevent your plant from getting unwanted stresses . I hope this information helps you on your quest to the finish !! Happy Growing!