We stay on a property during the school holidays on the Wakool River NSW ,it's great as we are the only ones there and it's so peaceful and quiet. We are making our way down there now very slowly
We found that the worst of it only lasts about 5 weeks, from just before Xmas to end January. Caravan park prices might be higher for longer, but the crowds ease off.
Our answer for that 5 weeks was inland towns - places like Ballarat, Bendigo, Toowoomba. Once January ended, we headed for the coast again.