For sauces, I'll generally dehydrate until the exposed side is dry to the touch.  On the sheet, this means that the back side will still be tacky.  While hot, I peal the sauce and reverse--tacky side up--and continue until dry.  Then remove while still warm.  It should still be plyable.  Fold down to baggy size and store in the frig until departure.  As it cools, it will become nearly rock hard.  To speed re hydration, tear into small pieces before mixing with liquid.

I begin my dehydration regime approximately 1 week prior to departure.  I transport in a cooler, but then I'm a 2-day's drive to a put-in.

dd