sometimes it does remain open but otherside is unperdictable. you may find it difficult to come back. so its not advisable. even if you proceed you wont be able to access the area beyond baralacha. Keylong would be the last safest halt. any snow fall at rohtang la can stop the movement between manali and keylong. and in that case you would have only one option to go towards kunzum pass (that remains open for 15-20 days more than rohtang,) and take the kaza-tabo-sangla route to come back safely.
why you are so particular about november? Nov is not the best/right time visit this section of himalaya. you would miss all the prehistorical stuff like caves and fossils due to just a single spell of snow. the road stays open for a longer period indeed but charm of nature goes under. the different shades of mountains etc wont be visible as clearer as till may to oct.
Thanks ravi for your response. I was in spiti before in july02 and sep06. Its wonderful. Heard about long and harsh winter with 6 feet snow around. Just want to visit this place as close to winter as possible without getting trapped. Guess nov is a safe bet. During my sep06 visit, locals informed that there has been significant climate change in SPITI, now this cold desert receives much more rainfall and correspondingly less snowfall. Duration and severity of winter is also less they say.
Hi! Spiti is reachable almost throughout the year,besides short periods of closure of the Hindustan-Tibet road in case of bad weather(like few days back). November is definitely cold,but the snow is supposed to fall later on,and in Kaza they have never seen 6 feet for sure. People go there all the time. In november there are very few visitors anyway,so it is easier to have contacts with the locals who are mainly free and it is party time.