By southern winter i meant Southern Australia, ie cold and miserable (cant really say wet anymore though, but it is a possibility). Once you get higher than the tropic of capricorn then the middle months will generally give the best weather, from a comfort point of view.
Do you know whether the games are to be/were played in the north, south or both, of the counties you mentioned? I would have thought that for one of the worlds showcase sporting events you would be looking to attempt to have the best conditions you can.
The point about the grass being a different length is interesting. I wasn't aware of that and can see how it would be problematic.