I went there last Feb, and you'll find it great! Lots of snow, less people!The Rainbow Inn was where I stayed, an amazing, cozy place with open musical nights!Though some routes may be blocked like the one to Tosh and Malana!
Dear friend, the least advisable time to head out to Kasol, the months between November and February bring in extremely chilly temperatures, which is not likely to give way to enjoyment. Wrapping yourself up with layers of warm clothes and sitting in the hotel room is undoubtedly something you do not look forward to before planning a vacation. With most of the roads being blocked due to heavy snowfall, only the daring plan a trip to Kasol in winter. Trekking to Kheerganga, Pin Parvati Pass, and Sar Pass is something you can do during these months. However, it is best to avoid Kasol in winter if you wish to spend some quality time in the midst of nature.
Its really chilly in that of year in kasol. You will witness snow capped mountains. If you are lucky enough than you will snow fall.
you can also go to kheerganga trek which is just 70 kms from kasol.