I suspect June 30th is unavailable due to either the Indy (set-up, etc.) or the event that is taking place at Ontario Place July 1st - 4th. The event is one of a series that are a part of Canada 150 celebrations and is featured at Ontario Place on 3 different weekends this summer. Not sure the reasoning behind the tailgate not going on during the Ex but perhaps the CNE itself had something to do with it -- either wanted the lot for CNE parking or they realized that they were missing out on alcohol sales at the tailgate and thus did something to prevent the Argos from having the lot.