"I myself won the game as a solo sorc and I don't think I picked *any* divination spells.. so I'd say it's very possible."
The thing is you don't really NEED any of the divination spells but it's what I'm forced to pick. Anyways I just finished irenicus' dungeon and some of the side quests, and it isn't too hard so far.
I just keep up Blur, Mirror Image, Stoneskin, Protection weapons, and a few shadow door spells and let loose on offensive spells.
Hardest fight was probably against the skeleton warrior in graveyard so far because of his really high magic resistance(Took 3 lower resists to reliable magic missile/fireball him to death)