Since you want to do a drive and it's the middle of winter, the Cairns-Arlie Beach/Mackay/Proserpine drive is probably the best option, then fly south. One major photo op you'd miss will be the Tropic of Capricorn (Rockhampton) Check out the
roadside monument in 2005
The other option would be fly Cairns-Brisbane, drive Brisbane-Sydney, You'd be able to go to the most easterly point in Australia (Byron Bay), the
Waterfall Way around Dorrigo is beautiful, and very different to tropical rainforests (you wouldn't have to do the whole thing, just around the Dorrigo bit would be enough), and there is a Big Banana at Coffs Harbour. BUT it would depend on the weather - if it's a wet winter, might be best to stick to driving Queensland, but if it is a dry winter you'll probably think it's great in NSW.
Going back to the north Queensland driving option, I haven't been for a long time, but I remember Mt Spec north of Townsville as very pretty. Townsville is in a strange dry belt, Mt Spec is where it goes wet tropical again to the north, close to Bowen to the south it goes wet tropical again. (Rockhampton is another dry belt). Tully, about half way between Cairns and Townsville, is generally regarded as the wettest place in Australia, it has a Big Gumboot (the height of the gumboot is the record rainfall in one year), though nearby Babinda also claims to be the wettest place in Australia. (Dorrigo, mentioned above, is the wettest place in NSW)
I think getting in a good long 'drive' is a great idea for seeing something different to the usual go from airport to airport.