My local independent pipe shop stores the bulk tobacco in large plastic bags under the shelves in the humidor below the cigars, but has most of them for sale in the big "candy jars" with soft cork gaskets on the tobacco display shelves. I presume the blends can sit in the candy jars for some time. But most tobacco can sustain a lot of drying and remain good to optimal. I often remember than the crew on the old square rigger sailing ships, at sea for months or years at a time, kept their personal tobacco in their sea chests in cloth bags with drawstrings, with a little hydration from the sea air below decks.