There's heaps going on in Queenstown for the winter. At night, there are plenty of bars and clubs to choose from, packed with tourists just there for a week skiing/riding, travellers working in town seasonally and locals.
The season lasts usually from June to September, so it's not as long as a northern hemisphere winter, but still good to fill the gap, particularly if you want to travel around NZ or Australia on either side before heading back to do another season. There are heaps of people in NZ and AUS that do back to back seasons, so it's pretty easy to settle in.
There are a few resorts to choose from - The Remarkables, Coronet Peak and Cardrona, and Treble Cone near Wanaka (my favourite, if you're looking for something steeper) is a bit further away. You can not stay in the resort like in Canada, but it only takes about 30 - 45 minutes to drive from Q'town to the closest resorts. If you are working, most people either pool rides or hitch (if you haven't got any mates with a car!)
This might help - http://www.tourism.net.nz/region/queenstown/
If you want to work, you might be a bit late for the first intake for the resorts (usually done around April/May), but as soon as the season kicks in, you can probably find work when you arrive. This might help - http://www.seasonalwork.co.nz/index.bsp about 10 years ago