Did Judas have the free will (in the libertarian sense) to not have betrayed Jesus, and if so, what would've happened had he chosen not to?

Did Judas have libertarian free will? If so, what would've happened to the salvation plan had he chosen not to betray Jesus? Would there have been no crucifixion, and therefore, no atonement, no forgiveness of sins, no salvation? On the other hand, if the betrayal was a 100% guaranteed thing, with Judas having no actual possibility whatsoever of **not** betraying Jesus, would that mean that Judas had no real free will, and if that's the case, then how can he be held accountable for his actions? I would like to know if there are philosophical explanations published by reputable Christian sources addressing this complex dilemma.