Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Hakuba (72% of total searches to Nagano Prefecture). The next most popular destinations are Nozawa Onsen (13%) and Yamanouchi (8%). Searches for hotels in Nagano (7%) are also popular.
KAYAK users have found double rooms in Nagano Prefecture for as cheap as $47 (Matsumoto) in the last 3 days. The average price is $400.