I was traveling with White World Expeditions last year in December. December is surely not the perfect month for visiting North India, in particular for kayaking or rafting on the freezing Ganges River ... but I did not discourage myself to try. The decision I made was my best choice ever!!!!
While discussing the trip itinerary the WWE-guide considered all my interests and wishes, weather conditions and kept the costs within the pre-defined budget. The organization of the trip was excellent, the guides were very professional, always helpful and open to suggestions, as well as prepared for unexpectable (e.g. weather changes).
Going for this trip I was not interested in a luxury accommodation but more in getting "real India" know. Getting local people know their habits, religion, daily-life, the overwhelming nature and of course having a lot of fun and adventure. The trip exceeded my expectations!!! We were rafting after sunrise on the Ganges river, praying in the old Indian temples, eating delicious local food (incl. "pori pori" - my favourite :-)), practicing yoga in an old Ashram, buying 100 oranges for 100 rupees in a small village on the foothills of Trans-Himalaya and debating of how to bring them down to our car. All in all ... it was an amazing time with a lot of memories and an incredible portion of fun! I can only recommend you to travel with WWE!!!