I'd really prefer localized long rests where you camp on the actual map. With a chance to be attacked by wandering monsters.
If there has to be a "base camp" that is in a safe mystery location you teleport to, you should only be able to access it from a safe area. If you are not in a safe area, you should take long rests in a makeshift camp. Or find some kind of campsite or shelter, like the Deep Gnome village or Myconic colony.