We spent three weeks traveling across the North and South, staying in a broad variety of places (Huka Lodge to B&Bs). The night at Helen's was the highlight of the trip, and is the only review I'm writing.
A completely unique place, beautiful, off the grid. Dinner was lovely. Helen is the only person living full time in Arthur's Pass and is basically queen of the valley.
The view of the mountains from the large central window is so beautiful it's almost surreal. We had a clear night and could see the entire milky way - breathtaking.
The lodge is designed to be sustainable -- solar power, joined wood, rainwater -- don't expect wifi and hotel mod cons. Do expect to feel absolutely refreshed and at peace for days after. I was extremely sad to leave. Don't miss staying here.