Well it might not be a stable with a manger but this shelter will be your friend on a cold winter night. Based on the Arctic Lean-to this kind of shelter has been used by travellers in the boreal north for generations. Easy to construct out of conifer at a steep enough angle (60-70 degrees) to shed the weather. Pair it with a raised bed of soft fir boughs for insulation, a long log fire and a fire reflector and you are good to go down well into the minuses.
Below is a step-by-step pictoral guide for this lean-to. It was done in a several hours by with spruce cross-beam, uprights and thatching and with bracken thatch that was close to hand. The bed has a retaining log to keep the soft fir boughs in place. Over the coming days it will be improved with more thatching layers, a better raised bed and a fire reflector for a long log fire. The overhanging uprights will also be trimmed to discourage rainwater travelling down them and into the shelter