We stayed for one night in the Coles Bay campground, where we were assigned a (lovely) spot, then we camped two nights in the Circuit.
We just spent 2 months in NZ where camping in national parks is very regulated. So we were intrigued to find lots of nice spots near the trail, but not in campgrounds. One couple had the most delicious spot on Wineglass Bay and we saw daybreak photography from the top of Graham Mountain. This is the situation in many of our National Forests, where you're permitted to camp just about anywhere.
Of course, we enjoy camping near a water supply, but what exactly are the rules?