Darwin was just the start of our Northern Territory travels. After three nights in the N.T. capital we were off and away in our camper van!
We actually had the van for the entirety of the trip, despite not sleeping in it the whole time. It was easier (and cheaper) to hire a camper van for 2 weeks than to mess around with a hire car some of the time and a van the rest. In fact, it was the same price to hire a camper van for 2 weeks, with the one way surcharge from Darwin to Cairns, as it would have been to hire a car.