Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Hakuba (35% of total searches to Nagano Prefecture). The next most popular destinations are Nagano (26%) and Karuizawa (21%). Searches for hotels in Matsumoto (18%) are also popular.
KAYAK users have found double rooms in Nagano Prefecture for as cheap as $35 (Karuizawa) in the last 3 days. The average price is $142.