I will frequently set a pipe down, only to revisit it later. They seem to taste a bit stronger after a "resting" for an hour or so. I seldom go longer than that. If I come back to a pipe that has been "resting" for an extended time (2 or more hours) I will empty and repack the bowl.
I suggest that if you know that you will not finish a full bowl, only pack a half bowl.
Waste not, Want not.