Auto-regen or potion can all be balanced. Classic example would be charges refilled after rest, there are not even mana points, just health/hit points. Auto-regen could be done if it's a more magic heavy build, since it's turn based, if you are in combat, it still gonna regen a specific amount based on your stat, if you flee, it could regen a bit faster. It can be tied to health(ie full health regen mana faster based on stats.) Potion can span through multiple turns, ie. heal x points per turn for next N turns base on potion power. Or a spell that trades you health( or henchman health) and converts to mana. It's all been done before.
