Having an "X days til you go mad" limit on male channelers would probably work in that case, then - Especially if it's in the decades before the main setting where there are more false Dragons proclaiming themselves, etc.
Though again I wonder if it would be a bit unfulfilling, even if there are canon conflicts to work with. At the end of the Aiel war Gitara would die, but nobody except Siuan and Moiraine could work to track down the Dragon, etc. So perhaps just a few centuries before where all the nations are in place but a lot of scope for conflict... the Andor/Cairhien border disputes, the fall of Hardan, the Tairen conquests of Mayene, a particularly bad incursion of Trollocs into the Borderlands one year, the Andoran Wars of Succession, room for non-canon nation-nation conflicts etc.
Plus since Aes Sedai tend to live for several centuries most canon characters wouldn't be born yet, while, say, Verin would already be over 100 in a Whitecloak War game. Also, the Aiel being able to trade with the Cairhienin is just as good as a hook for having at least a few of them as the war stuff, and if people want to play "exotic/cool" nations, well, the Malkieri would be available at this time. 