In reply to TheBigFactHunt:
Many years ago I went several times to the French Pyrenees in winter. There were many cabanes/shepherd's huts (marked on the maps), in addition the refuges, including those wardened in summer, were all at least partially open usually with dampish mattresses and there was usually no charge, One or two even had free canister gas stovesgas stoves. A good sleeping bag and a karrimat was always sufficient. In the valleys we could find somewhere adequate to sleep eg open fronted bus garage or under a lorry.