Hi Lucia Lee,
you will need practically all that you will need for a fifteen or twenty-five day trip but might be able to skip some spares. No matter where you intend to start or finish you will need: good quality water-proofing, either a shell top and trousers or a quality poncho and gaiters / trousers; multiple warm mid-layers and possibly a thermal base-layer. (warm undies, good woolies, stout trousers and sound waterproofs). You will need a waterproof back-pack (though stow all your gear in waterproof bags inside your pack just in case. You will need well broken-in waterproof hiking boots or shoes. I would recommend carrying an, at least two-season, sleeping bag. Not all Albergues are heated though most can provide blankets. You will probably have little need for sun-block unless you are walking on sunlit snow, in which case it is an essential. You will need a water supply and I would recommend carrying some high energy foodstuffs, Musli bars and the ilk.
If you put "packing-list" into the search facility on this forum you will find plenty of variations on the above suggestions. But the essential elements of winter hiking remain: Dry, warm, watered and fed survives, and thrives.
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