Don't loose track of time after that. Now, the days are getting numbered. So, be careful and return well in advance and establish yourself here. Get a Job, and get all of the things, such as SIN Card, Health (OHIP, if in Ontario) Card, A Driver's licence, a credit Card etc., here in Canada after your arrival. (The Second Time)
In case you are not going to be in Ontario for the first six months after landing, then you should not apply for OHIP.