Long Rest

long rest is a period of recuperation, at least 8 hours long, during which a creature does nothing more strenuous than eating, drinking, sleeping, reading, binding wounds, and standing watch. At the end of a long rest, a creature regains all lost hit points and spirit points. In addition, it might reduce its level of exhaustion.

Hit Point Minimum: A creature must have at least 1 hit point at the start of the long rest to gain its benefits.

Can't Be Deprived: A creature that hasn't satisfied its daily need for food, water, and sleep gains no benefits from finishing a long rest.

Once per Day Limit: After finishing a long rest, a creature must wait at least 12 hours before it can start another one.\ Do Not Disturb: If the long rest is interrupted by combat or by at least 1 hour of walking, casting spells, or similar activity, the creature must begin the rest again to gain its benefits. If the rest was at least 10 minutes long before the interruption, it counts as a short rest.

The heroes can be expected to survive one or two challenging battles (and countless easy ones) before they need to take a long rest.