Buy this ticket on top of your ticket WITH accomodation or a Karma Yogi ticket.
We have this year the option to sleep in one of the outdoor cabins. They stand in a circle between the trees, a little away from the main buildings. They offer a cosy place with a little more privacy. They are quite basic, and unheated, so make sure you bring a warm sleeping bag! The building with toilets and showers are in the same circle, and these are heated.