At a relaxed pace, including a few days in each major city I'd allow at least 3 weeks.
I'm not sure on the best places to stop from Sydney to Adelaide but Adelaide-Melbourne id stop at Kangaroo Island 2 days, Robe, Mt Gambier, Warrnambool, Port Campbell, Lorne, Melbourne, Phillip Island, Wilson's Prom, Lakes Entrance, Eden then maybe 2 more stops before Sydney that someone more familiar could suggest. This allows for only a few hours driving per day and plenty of sightseeing time.
You could cut this down to less time but it would mean increasing the driving distances each day and it would no longer be a relaxed pace.
I'm sure you know that's one of those "how long is a piece of string" questions, open to everyone's interpretation of "leisurely pace", travelling style & more.
My off the cuff answer is "about a month" if you want to stop here & there to explore ...
When you are planning the trip may influence my and others' recommendations, too.
Which leads me to your next question " where to stop & what to see". That depends in very large part on your particular interests. There's enough to see & do to fill 3-4 months or more if you wanted.
Rather than trying to guess what you might like - let me ask you, what made you think this might be an interesting drive?
What would you hope to experience?Edited: 27 July 2014, 00:02
A couple of hours away are the beautiful Southern Highlands, further down the highway is a classic country town in Goulburn where you have to see the Big Merino. If you are passing Jugiong at lunchtime the is a lovely country cafe The Long Track Pantry.
Driving will take you along the Hay Plain - a long stretch of nothing - flat featureless countryside but nothing like you'll see in the UK
Stay in Mildura ( about 12 hrs driving from Sydney) on a house boat for a few nights and have some delicious local food and wine. Travel up and down the Murray River and see some beautiful Australian scenery ( lunch at Trentham Winery on the banks of the Murray is lovely on a clear day) or if the budget doesn't stretch there are beautiful caravan parks along the Murray.
A trip to Mungo National Park - about 2hrs north east of Mildura - is also special - be sure to see the Walls of China.
South Australia boasts some great wineries around if your interests lie there.
Hope that helps
It IS a "piece of string question" :-) But LOstris's "3 weeks" is not a bad minimum for a leisurely trip. Hubby and I did a similar drive years ago, 3 weeks to Adelaide and back along the coast via Melbourne, the difference being our loop was from Canberra not Sydney. If you have at least that much time available I am sure you will get lots more great suggestions of what to include here.
I don't think even that is feasible in 10 days. I mean I guess you could rush and tick off things but that's not very sensible and didn't sound like what you wanted anyway. Do you have flights booked? It would help if you could fly out of Melbourne instead of needing to return to Sydney. What exactly are your priorities for the trip, what do you want to see and do?
Flights are booked in and out of Sydney I am afraid. I am really not sure what I want to do. Over 60 so nothing very strenuous! Just exploring and maybe take in a winery or two. Would like to find one on the route that does accommodation and food if possible.
I'd really think about doing an internal flight or two. If you want to do a road trip or see a bit of the coastline then I would make that just a part of your trip, not the whole trip. So the task is to identify which locations/attractions/etc to include, and put them together in a day-by-day itinerary.
The main wine regions on your route are the Hunter Valley near Sydney and the Yarra Valley near Melbourne, but there are others, including quite a few wineries around Canberra, also on the south coast. A winery with accommodation and dining would narrow things down, do you have any particular preference for type of wine? I'm just thinking aloud here, trying to get more specifics so that we can make the best suggestions for you.
Oh, I don't think you've said when?
It will be like one of those bus tours I have been on from London through Europe. You spend a lot of time on the coach staring out the window without experiencing very much at all.
If you want wineries on your inland route from Sydney to Melbourne do not miss Rutherglen, near Albury Wodongs
My favourite on that list is All Saints
Off on it's own is my favourite winery of all, it is Brown Brothers. I used to live just over 10 minutes drive from Brown Brothers.
You can divert to Milawa from the Hume Highway, near Wangaratta.
Hunter Valley is great for wines and a few spots have accommodation too.
If you are in the area, then I agree with the Browns Brothers suggestion above. They have a stunning range for tasting, including a good selection of sweeter and dessert wines. The area around Browns Brothers has lots of foodie stops too - a mustard maker, cheese factory, olive shop etc...
One option would be to drive down to Melbourne via the coast - nights in Kangaroo Valley/Jervis Bay, merimbula, Lakes Entrance. Few nights in Melbourne and then back via the hulme highway, visit Yarra valley or wineries such as browns brothers, stay near Albury then Canberra then Sydney.
That isn't relaxed, but it certainly isn't break neck pace!
Alternatively you could do a much more sedate loop from Sydney Blue Mtns, Hunter Valley, Port Stephens, then south to Kangaroo Valley and Canberra.