I know this post is too late for most to use this year. But the knowledge could save your life. Any one that spends time out in nature when it is cold should know how to make shelter in any condition.
First and most important step is to find a good location. Do not put your snow shelter between trees or against trees. Trees flex from the wind and can cause cave in.
Next thing to consider is this shelter is to keep you alive not keep you comfortable. Start by piling snow in one spot. Keep compacting it down, snow shoes or just keep stomping it down. This binds the snow molecules together making for a stronger safer structure. Don’t make it too big just big enough for you or your small group. My mound is too big just for me, I wanted my kids to be able to play with it when I was done.
Now once it is piled and compacted, let it sit for 10 min or so. This will allow for it to harden. Now start cleaning the snow for the door, make sure the door is just big enough for you to fit in. Door placement should also be facing away from any wind. When the door is chosen start removing snow from the inside of your shelter. Just enough for you to sit up inside. Long enough for you to lay down and wide enough for you and any gear you may have to cover the door once inside. Ensure you dig the bottom snow to as bare of ground as possible. This is a vary important step, the ground gives off 17°f ambient temperature no matter the outside temperature.
Some required items that are always in my pack are a small collapsible shovel, candle and weather proof matches, light to mid weight sleeping bag. This is just a minimum.
I have spent the night inside one of these at -40°f, like I said not comfortable but I am still here to tell you about it.
