When we did the Melbs-Brissy drive, we did it over 4 days, alternating between 3 and 8 hours each day. Not deliberately, but based on where our free accomm was!

We left Melbs at 4:30pm Friday, and drove a bit past Mansfield. Stayed in a cousin's caravan. [2.5 hours, I think]
Left Mansfield next day, quick visit with DH's grandparents on the way, then up through Wagga, Bathurst, to Hill End, to stay with a friend. [8 hours total driving]
Next day detoured through Mudgee, lots of cheese places and wineries (pre-vegan days!) and then up to my nan in Gunndah. [3 hours total]
Next day did the 6 or 7 hours to Brissy. Most boring day of the lot, but exciting because we were nearly there. That was on the Newell.

My nan and sister both hate the Newell because there's heaps of trucks. But I would slowly remove my own head with a nail file before ever driving the Hume again.

Have FUN!