there are some private campsites around you can stay, or you can stay in Darlington Provicial park which on its way, or worst or worse, come back to Toronto.
http://www.ontarioparks.com/english/darl.html
http://www.ricelakecanada.com/
http://www.ontarioparks.com/english/darl.html
http://www.ricelakecanada.com/