I started planning for it, only to discover that, it is just not possible to plan for Kolkata trip during Durga puja days. :-(
I had some hope since I had almost a month to plan for it. But to my surprise, I found that there are no tickets available (neither by air nor by rail) to travel there and to add to it, all hotels there are booked as well. I never felt so bad about anything.
After talking to Indraneel, who is from Kolkata, I discovered that one month is not at all sufficient to plan for Durga Puja. Every Bengali person on earth tries to travel to Kolkata during that time.
Note to myself - Plan for it at least four months in advance in the next year. Meanwhile take a look at this to see how is it in Kolkata during Durga Puja. You will have to click on the images in the left side.