I'm not sure where the answer to this is but I really want to be able to effectively use a one hand only with spells for thematic reasons. Honestly though, before reading the forums I hadn't even considered it. It was 1h/shield or two hand or dual wield. In Skyrim I did 1h and spell... So while it rankles me that 1h and open slot is an oddity that isn't viable, I'm curious how important it is to the game.
The talent idea was pretty solid, and a talent might be where we find this.
Take into account that the talent must also offer additional benefit over and above parity with other options because you're spending a talent point. So actually, double stat bonuses may be an elegant solution. Because you now have greater control over the stats you're boosting which may be slightly better than two items worth of stats.
You could also try stat boosting non weapons in the off hand - like talismans and severed limbs of monsters.
