I think Lee will die. I've read the comics and this isn't a happy-ending kind of story. Lee's fate is pretty much sealed. We know what's going to happen. You can be in disbelief like Kenny was about Duck, all you want, but it's not going to change the fact that he's been bitten and that bites are fatal unless immediately amputated, which he didn't do.
Perhaps his story will end with him knowing that Clem gets saved or that her mom really is alive or that he can leave her with someone to protect her before he dies.