I think for the sake of simplicity there should simply be â€˜zonesâ€™ where you cannot long rest, until all enemies are cleared. For instance the goblin village, the underdark, any large dungeon or tower etc. That makes those regions more challenging, and short rests and other resources become far more valuable (spell slots, scrolls, potions etc). No different to the bandit camps or subjugated villages in Witcher 3 â€“ you canâ€™t meditate until the area is â€˜safeâ€™ which is often marked by villagers returning etc.
Sure, you can run your ass back out and find somewhere that you can long rest, but if you head back in youâ€™d better be sure youâ€™re ready.