It does not necessarily provide comfort, convenience, aesthetics, or enjoyment. In its most basic form, it offers pure survival. Emergency conditions dictate a reasoned compromise between that survival and the extra time and energy consumed trying to make something spacious and comfortable.
Wind is one of the biggest factors in heat loss.
A barrier to the wind is an important function of any emergency shelter. If you have ample snow, wind walls or even more elaborate shelters can be made to deflect the chilling gale. Don't overlook simple natural protection like boulders, upturned trees, or any other natural barrier to the wind. Orient the entrance of a freestanding snow structure downwind. Protection from moisture should be your next consideration.