Well, now that we are on the topic of solo vs group, I will add my two cents. In serious winter conditions, solo is simply not safe. Particularly on longer trips, say a week or more. Summer conditions are forgiving, winter not. I have had my hands get cold enough that I could not manipulate a zipper. You also need someone who can observe you and see if you are getting hypothermic or frost bite. There are all sorts of little things that can go wrong in the winter that will kill you. Every year someone at a ski area drops into a tree well and smothers, unable to get themselves out. What if you post-hole into a stream and cannot get your foot free? And what if partially burried by an avalanche? A lot of people think they can extract themselves from precarious winter situations but have never really done so. I have been totally humbled by winter conditions. None of us is perfect- we all make mistakes. There really is safety in numbers in the winter. And with a group of four you can well afford the extra weight of bringing one good shovel. And a bonus is company on those long winter nights! Just pick competent partners that you like to be with.