We hadn't skied in NZ since 2005 when we lived in Sydney. As we were going back visiting family, and well, Queenstown isn't far from Sydney, we jumped on a plane and headed to Wanaka in the last week of July.
Luckily we arrived when the snow did and the conditions were quite superb. There's a tonne of pics on my blog at https://gortonator.wordpress.com/2016/08/16/5-wonderful-days-in-new-zealand/
Here's some additional info/thoughts:
Wanaka is a quieter version of Queenstown, less touristy but still with plenty of excellent food and bars. It's also central for both Treble Cone (TC) and Cardrona. TC gets probably the best snow of any NZ resort, and is a decent sized, varied area with some serious challenge. I absolutely love skiing there, and its chutes and gullies and off-piste are great. The frontside is served by a 6 pack with good vertical, and the back Saddle Basin has a fixed quad, less vertical but some truly great riding.
Cardona is smaller and gets less snow, but in conditions like this year there was still plenty of terrain to play on. It's more an intermediate mountain with a few steep chutes through the middle, but with good cover there's plenty of fun to be had. I think generally it gets busier then TC due to be more forgiving, easier access road, and much nearer Queenstown. The lift system has two main high speed quads, with the lower mountain served by a fixed grip quad. less vertical than TC, but plenty of groomers and variety.
Both mountains are treeless so when the weather is stormy, visibility is limited and winds can close lifts. We were lucky on this trip and skied every day - when one mountain was closed or delayed the other was open. This is a good feature of staying in Wanaka.
Talking of access roads, apart from some limited condos at Cardrona, all the ski hills are day areas where you drive up, The road to TC is steepish and narrow and unsealed. They do a good job on it and it's wide enough not to be too scary. We hire a 4WD which helps, otherwise you will be fitting chains a lot. We had so much snow we had to fit chains on the Prado this time - a first. Cardrona is a gentler, wider access road, and when the snow is low enough, there's a lower parking lot which saves a 10-15 minute drive up to the top of the hill. Both are 45 mins from Wanaka to parking lot on a good day.
In general NZ skiing is still on the slightly primitive side. The seriously snowy stuff needs a helicopter to get to, There's lots of options for that if you can afford it.