For short trips, a week or less, I'd rub it out and keep it in a baggie in your pipe kit. For longer trips, I'd put the flake (rope, plug, coin) in a baggie and carry an old tin for rubbing out. Tobacco travels better than you'd think. It wouldn't have been popular among old square rigger sailors if it didn't, especially under the miserable, humid, hot, messy conditions under which they lived. It was one of their few luxuries, so our travel conditions are posh by comparison. The airlines torment us endlessly, but not our tobacco.