Well 2020 is the T20 World Cup so i imagine they might be upgrading for then at the latest.I think most people will agree that now really isn't the time to upgrade the stadium but its good to be talking about it with the GWS and Thunder only getting bigger. I'd say see how the next two seasons go crowd wise for both footy and cricket then plan from there, 2020 would probably be about the right time to start construction