We fly in to Darwin from Bali around the first of November. We were wanting to rent a car and drive (over a period of 2-3 weeks) to Sydney. Is this doable? How far is it? Will this cost a fortune in fuel? Is there much to see between Darwin and Cairns? Thanks!
November is the start (or rather the so-called 'built-up') of the rainy season and although it might still be fine, roads could flood from that month onwards to April or so.
The wet season usually starts a bit later in Cairns and is less heavy. I would seriously advice to book another domestic flight and start in Cairns.
There is a lot to see between Darwin (especially at the start in the Top End) and some nice Outback scenery on your way east, but with only 2-3 weeks it is rushing it. Cairns to Sydney in 2-3 weeks though is fine, although you have to make choices again.
Another reason to choose for Cairns, is the cost of a rental car. A regular (the cheapest classes) car is much more expensive to rent in the Northern Territory (and Western Australia, except Perth) compared to the east and south of the country. Also, if returning the car outside the NT/Western Australia, you pay sometimes huge dropoff costs as well. Not so if renting one in Cairns and returning in Sydney.
So: rainy season start, less km from Cairns, much lower rental (and drop off) rates means that Cairns to Sydney would be much much better to go for!
Cheers and have fun
i just spent 4 months working in darwin in tourism if you need any help let me know