My situation is similar with you. TOEFL: 250/4.5, no GRE, GPA 85%.
Computer Science of UofT definitely need 5. I have tried to called ECE department, a lady told me that they need 4. But a person i know in undergraduate study of this department told me that basically they need 5 because of the competition. Maybe you should go to UofT by yourself and get some real information to see how much possibility you could have to join them.