I've heard of this before. Ruepehu has some of the characteristics of Bachelor. It's an isolated volcanic cone with violent winds and frequent lift closures midwinter. But it usually gets more snow that the South Island lift service, which is all leeward of taller mountains. Also Ruepehu is ~4 hours drive from a fair sized First World urban area in Auckland. Which means daytrippers and weekenders will actually show up for spring skiing in big years, unlike Portillo and Valle Nevado, which surely had the snow to run late in 2005.
Turoa is on the SW side and should hold the snow longer. Its season extends into November fairly often. And I think one of those areas reopened for Christmas-to-New-Year's after the last big NZ season in 2004. Perhaps I should bring ski boots along for the November 2012 eclipse trip to Australia/NZ.