I'm rather surprised that no one (to my knowledge) has suggested lamps as an alternative personal light source, or even the option for a single handed torch.
While torches weren't as practical to carry in the middle ages for every day needs, lamps were quite common through all walks of life and were practically a necessity. Being able to equip a lamp in one's hand (possibly by making use of one of the two waist slots), it would help to radiate a fair amount of light even while hung, though of course could provide more if held aloft either by hand or via a pole.
I'm hoping to get something a little bit more manageable than the bloody 'poles' that have to be strapped to your back in the game's current form, though I would be willing to settle even for a single-handed torch that could be held in the off hand.