Andy as i live nearby and frequent various dark sites i can give you an opinion. It depends. It depends on your actual location, as the Hunter Valley runs from above Scone right down to near the coast. Where are you thinking of staying?
Obviously you want to avoid major light sources, like Muswellbrook, and the power plants nearby. Operating open pit mines tend to be light sources. If your in the winery region it will be better, but i believe the best sky is probably up around Scone at the top of the Valley. Lake Glenbawn, north east of Scone, is pretty dark, you can only detect a slight light dome in the direction of Muswellbrook.
As Atmos suggested, narrowband always works, and i would pack for that. If you get co-operative moon rise/set times then broadband will be ok. Suggest you look at the global light pollution map and find the location where your staying on that.
http://www.lightpollutionmap.info/#z...ayers=B0TFFFFF
BTW the SQM reading in my backyard is regularly 20.9+, so don't think it is going to be shockingly bad up in the Valley, as long as you are away from town centres like Singleton, Muswellbrook, and Cessnock.
Edit, i just had a look at the moon set times from 22nd Dec, (21:50), so even allowing for conversion of that to DST, the best nights might be the ones from the 22nd to 25th when you can get descent dark periods. After that the moon is unavoidable and getting bigger, so narrowband only. This assumes that you, and your wife, are ok with you being out imaging late on your holidays.
