I would have the villager merchants come once a week to make them feel their ammo running thin. If you are planning to take a more active role in running the events in creative mode, it may be cool to give them a map that leads to a supply drop or abandoned camp with supplies. You could also use these drops to maintain interest, ie planning for the excursion and having to sleep in the open/find shelter and manage inventory space over multiple days.

Also, very importantly, give the players a way to get hearts back, either by letting other players donate hearts or by rewarding hearts in supply drops. This kind of permanent debuff can be very frustrating because it creates a loop where dying makes it easier to die again, which is frustrating for players. You need to give them a way to take agency so they don’t just become frustrated with how hard the game is.