Jail seems most likely.

Hard to see him escaping in a way that is satisfying from a story telling perspective after the parallels to Walt and being forced to confront what he has become at Marion’s. There is also no salvaging his relationship with Kim and he has done so much evil that it’s hard to see him finding a satisfying life on the lam. He’s basically been a shell of a man since Kim left him. I think they would have just left him as Omaha Gene if this is where the story was going.

Also, suicide seems out of character for him and there don’t seem to be any characters with a compelling motive to kill him.

I think he gets caught and Kim probably plays a role in it. And I agree with what others have said about him thriving in prison, so maybe there’s your semblance of a happy ending.