I studied abroad in Dunedin about a year ago. It's a blast, you will party so much. Dunedin is just nuts and known for a party uni. They have a party every year that people sometimes travel from Australia to.
Geography wise being located on the southern island is prime for partaking in outdoor activities, especially tramping. There is surfing close by also. Just a warning if you do decided to go, the flats you live in during the winter are fucking cold, like wake up in the morning with frost on the kitchen counters cold.
It is pretty far from Cardies and Treblecone but they have buses that you can take down weekly or buy a van with some buddies. The skiing will NOT compare to Europe in snowfall amounts and terrain.
Bottom line, if you are just looking for skiing in a study abroad experience go to Europe (Austria). If you are looking for some of the most scenic geography in the world and want to do more than just ski go to NZ.
Me and my buddy took a 6000 km road trip (after Uni) around NZ starting from the very bottom and ending up and the most northern point so if you have any questions I'd be more than willing to help.