Ok.  What about this?
SR = reset special abilities and warlock spell slots, etc,. Lift the limit entirely.  No 2/day.  You can SR as much as you want.
But it doesn't heal.  😮
Now, go back to food heals, but it ONLY heals outside of combat.  1 Camping Supply = 1 HP healed.
Now, add to this Long Rest requires the same amount as SR, basically 1 Camping Supply per 1 HP, but it costs an additional 40 because of spell slots, etc.