They're running the race in Northern Hemisphere summer (hence, Southern Hemisphere winter), which would make legs south of the Equator (ie Australia, most of South America, southern Africa), highly unlikely
. If they were to cross it, I don't think it would be for a giant leap (ie Oceania, South Africa).
That being said, I think they might go to Central America. It's been relatively unvisited plus they have TARLA racing down there to throw off any spoiler hounds like, say, us