Hmm, perhaps instead of generating a new schedule,, you coulld have some manual edge case for specific NPC(s)? Perhaps design a villager (or use Mirel since she's usually only around half the time anyway otherwise) with their whole purpose being that at high relationship instead of giving the player house keys, they ask to move in and live with the player? Then you can just have a manually made 'lives with player' schedule for them, though it might have to generate some sort of pathing for navigating whatever players may have done to the shed.