Yeah, Endurance can go fast, but can also be recovered pretty easily (spend 10min resting and having old canned beans or a swing of whiskey). I wanted to encourage players to always scavange for food and drink so they can recover Endurance quickly. Also, I want the players to consider how they tackle the problem. Going head on might require a Hard roll, and some players (especially when low on Endurance), will try to find alternative approaches.
Let me know if your group runs into problems if you play it. The only time it was played so far was with me running it, so I kept giving players some advice. So I am up for all feedback from other groups :)