i will bust my brain as its been 10 yrs since i done that road trip last (and in reverse, syd to melb!) it is do-able with bub, i remember we left petersham in syd at 6:30am and with a few stops we arrived in oakliegh arround 6-7 that night just give you a idea on times.
i remember 2 stops we made off the top of my head, one was a little place, violet town had a nice quiet park we stoped at, and another i cant qwuiet remember, it had a old submarine i think, something to do with the war? ill do some more thinking, and ask my aunty ill be back!!