The question whether God could and would have forgiven a repentant Judas seems obvious to me: of course He could and would have. Judas did not commit "the unpardonable sin". However, the Gospels, Acts and other passages leave the strong impression that, as Alba notes, Judas did not seek forgiveness.
Still, I am fully prepared to be surprised by those I encounter in heaven, just as there may be some who are dumbfounded to find me there. If one suggested on this forum that Hillary Clinton, for example, will be in heaven, howls of outraged derision would ensue; but she names the name of Jesus and claims salvation. Only God knows, and His grace is bounteous beyond measure.
Even though it is not mentioned - perhaps that question simply wasn’t known by anyone except Judas and God - it is not out of the realm of possibility as Judas’ main recorded actions indicate a dramatic level of remorse for his treachery. Peter as well denied Christ…once within the gaze of Christ as he did it. We know he was forgiven for it as Peter picked up and soldiered on, he continued in this realm. There are implications in the story that open up the possibility of forgiveness…as there implications, including Judas’ final act, that work against that.
I think of a very funny line in Annie Hall, where Woody Allen’s mother takes a distraught young Woody to the doctor because he is so depressed about the universe expanding until it blows apart, ending everything…his mother exclaims to him in front of the cigarette puffing doctor: “How is that any of your business!”