Like what you said Shaz its a huge day 1016km Sydney to Mildura. I know I'll be sharing the driving with my wife and I have traveled that distance in one day a couple times before, once towing a boat. 
We might need some input from the guys from SA who have done the trip many of time before rikkir, Carmikey, GT Hardtop and Ess Dub ?

The only boring as hell bit is the Hey Plains.  Otherwise, there are towns every 250km or so that you can stop at for an hour, then carry on.
 
Just don't drive across there at dusk/dawn - unless you want a roo as a hood ornament O.o

Or windscreen ornament.

while I often have done Adl/Syd Syd/Adl in one hit, sometimes alone, it's 1500k's. I reckon the Hume highway is the most boring part, as you're just making distance to get somewhere at that stage.. If the cars are running well, the Snowy Mountains Highway might be worth a day long diversion, staying somewhere near Tumut or Adelong on Day 1. Look around and stroll to Mildura Day 2 and run into town Day 3. Or head for Hay and stop in Wagga or Naranderra (or Griffith, coming the other way) if you've had enough. Mildura is a big ask, coming from Sydney, particularly for a group on a day trip.
 
On the way back, the best two day trek is take the freeway to Tailem Bend, go through Lameroo, Pinaroo, Ouyen and Managatang. Depending on how you're feeling stop at Tooleybuc, Balranald, Hay, Naranderra or Griffith. What people don't realise is that most of these places are on the river and have wonderful accommodation. 
e.g. https://www.stayz.com.au/accommodation/nsw/murray-riverina/hay/102306. 
Which would suit you all and there is large garage on site.
Really just depends on when you leave and how tired you are when you start. At least one of the days is going to be a long drive. 

Thanks for the dusk/dawn advice Essdub.
For me, more reason to do the trip with 2 stops.

 
2 day trip = :(
3 day trip = :)
What do you think ?
 
PS. No stress I'm on holidays 

nick12
while I often have done Adl/Syd Syd/Adl in one hit, sometimes alone, it's 1500k's. I reckon the Hume highway is the most boring part, as you're just making distance to get somewhere at that stage.. If the cars are running well, the Snowy Mountains Highway might be worth a day long diversion, staying somewhere near Tumut or Adelong on Day 1. Look around and stroll to Mildura Day 2 and run into town Day 3. Or head for Hay and stop in Wagga or Naranderra (or Griffith, coming the other way) if you've had enough. Mildura is a big ask, coming from Sydney, particularly for a group on a day trip.
 
On the way back, the best two day trek is take the freeway to Tailem Bend, go through Lameroo, Pinaroo, Ouyen and Managatang. Depending on how you're feeling stop at Tooleybuc, Balranald, Hay, Naranderra or Griffith. What people don't realise is that most of these places are on the river and have wonderful accommodation. 
e.g. https://www.stayz.com.au/accommodation/nsw/murray-riverina/hay/102306. 
Which would suit you all and there is large garage on site.
Really just depends on when you leave and how tired you are when you start. At least one of the days is going to be a long drive. 

Thanks for that Nick.  I do like to have my accom booked before I leave, instead of just winging it, but that's just me.  I have booked my accom at Adelaide for the extra night, to do the extra day sight seeing to Victor Harbour.  But if no-one else is staying, I could probably cancel that night & just head back from Tailem Bend.
JC & Eddie, are you sure you want to do it with just 1 stop on the way over?  If we stopped overnight at Balranald, that would give you between 800 - 900 km depending on your location in Sydney & which way you go.  Then between 520 & 550km depending on whether we went via Mildura or the more southern route via Tooleybuc & Pinnaroo.  Those distances are on google maps & I don't know the roads, so would be happy for suggestions as to which ones to take.
 

Fast Eddie
 
2 day trip = :(
3 day trip = :)
What do you think ?
 
PS. No stress I'm on holidays 

I'm a definite 3 day trip.  we were obviously typing at the same time.

Got 1 probable & 2 couple's who said maybe last night.  
 
Shall we make it a 3 day?  With Wednesday at Wagga & Thursday at Mildura?
 
Any QLD guys doing the trip via Mildura & want to meet us there?  

Sounds like a do-able.