Here is the bottomless cage mine lived in last winter. Same as what @Skyle said - protect from wind, put some hey on the ground and they will be ok in the winter. Laying eggs is more light dependent than temperature
The structure of the cage is metal, then net, then glass/plastic foil to keep them warm. In the summer I remove the foil.
The structure of the cage is metal, then net, then glass/plastic foil to keep them warm. In the summer I remove the foil.