They seem to be going for the 'Winter is coming' approach
Interesting though, we haven't had too many episodes set in the winter.
Aye, 9 seasons in an no mention of any real attrition due to the elements or lack of resources/food really. Bar the odd comment that they haven't got any to spare. It would have added another facet to the story. They always appear to be able to find batteries for the troches!