Stay in Kigwema. Vishwema has almost nothing. Contact Rovi at 8575826863. She is a wonderful host. You can't book private rooms n Dzukou Valley. Chances are the by the time you reach there, everything will be full because travel operators book everything in advance. There are two large dorms where temperature reaches zero on odd nights. They rent blankets and mattresses. Make two of each (or may be three).