Warwick farm is near Liverpool, on the south western side of Sydney. It is served by a train service (to Liverpool and Campbelltown) if you decide to stay in the city, or you can drive out on the M5. Incidentally, Chipping Norton is a suburb almost next to Warwick Farm (there, that is a helpful tip, I'm sure!)

As to where to stay? There are motels nearby, and a Formula 1 at Casula (about 6-7 kms away). Some of the more expensive chains are to be found on the Hume Highway near Bankstown --- and the Bankstown Sports Club has a motel attached. Bankstown is on the train line. Can't advise to the top end of the range if you happen to beat the bookies soundly