Depending on the deepness of the snow i would also look into plus size bikes. I have the trek stache and it shreds on dry rocky trails while also handling snow well, its not as good in the snow but it is very good for everything else. I have rode everything from endure trails, xc races and gravel roads on it and love it. It could be something to look into.
When riding any bike from road to mountain and eduro, i love my tioga seats. They are definitely something to wear with bike shorts, but they are very comfortable and have play for movement in the unique design of the seat. The models do change a litttle bit, but i have the spider outland and i use it for everything and love it.