Have you considered somewhere up around Karuah , a few motels there who wont car if you run an extension cord out at night to set up a scope after they turn the lights off.
Or Werakata National Park
http://www.environment.nsw.gov.au/Na....aspx?id=N0126
Or Copeland Tops State Conservation Area
http://www.environment.nsw.gov.au/Na....aspx?id=N0694
might have a sight where you set up a tent on caravan spot .