I really think that Lee's going to die in the end of this season. In a ultimate choice like " Save your ass or save Clem". And Save Clem it's probaly going to be cannonic. About Kenny, I don't know... He might die trying to protect his family in a noble act ( And then, the forum will be full of people saying that respects him or something, even after he being an ass with some of 'em).
But, who know? Telltale might surprise everyone.