Still, from what I saw, one does not simply go "no more resting" and then the game is great. You would have to change how skills work and rebalance all battles accordingly. It would need a "Stratagems of Sword Coast"-like mod on top of the God Challenge.
It would, but just making priest/druid/wizard spells per-rest would already help immensely, without changing anything else. Rest discipline would be self-imposed, just like in P1 and the IE games (except you'd still get to enjoy the food bonuses). This change alone would make me for one a much happier camper.
On top of that, I would rebalance Veteran and PotD. Slash the high-level enemy hit points by half or more (perhaps also some of their defences?) but bump up their attacks to match -- as it is, it takes forever and a day for them to chip away at my defences too. Smarter AI would be the cherry on top.
(The dumb main quest and dopey writing is there to stay of course, but then Baldur's Gate 2 was no Dostoevskian masterpiece illustrating the human condition either.)