All depends what "we" think.. how many orders do we think for Aust? (not reservations, there will be a lot more of those than actual orders). Also, do we think that Tesla will bring more cars out in anticipation of those reservations converting to orders over the next few months? Or just ship 'em JIT?
My guess, fwiw, is ~5000 reservations and ~1000 orders as of now. I have heard reservations estimates up to 8000 in the past (as well as much greater and less believable numbers)
One thing that is known and not guessed: Tesla really likes to get orders fulfilled as end-of-quarter approaches to get numbers on the books, so they will do their damnedest to get those cars shipped over by mid-end Sept.