Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Queenstown (52% of total searches to South Island). The next most popular destinations are Christchurch (25%) and Te Anau (12%). Searches for hotels in Wanaka (12%) are also popular.
KAYAK users have found double rooms in South Island for as cheap as C$ 32 (Queenstown) in the last 3 days. The average price is C$ 242.