Mate, Go the south Island all the way.
Mount Hutt currently has about 180cm base, and they were closed today 'cos of ####y weather and snow showers. There are quite a few feilds in driving range around Canterbury, and also The Queenstown area. Queenstown is really touristy, and farking expensive. The tourists don't seen to mind, but I do. I'm a Canterbury boy from way back, so I'm biased. If you don't mind nutcrackers, check out temple basin. I haven't been there personally, but it's suposed to be the best in the country.
Depending on how long you have, you could always drive down to Queenstown, or up to canterbury part way through.
This is our best snow season for years. I am bitter that having a mortgage means I couldn't buy a season pass this year.