Specifically, I'm referring to the idea seen in the Last Temptation of Christ, that Judas was the best buddy of Jesus, and simply playing a necessary role that both were in agreement on. And consequently, that he isn't the great betrayer, but actually quite noble in a sense.
I recall that there is a Gnostic "Gospel of Judas" that was found, which follows a similar vein, so there were clearly people early on in Christian thought who expressed the belief, but I'm assuming it was heretical and stamped out, or at least driven underground, so I'm mainly curious on whether this viewpoint on the role of Judas had any predominant proponents, or was debated at least, in the the Medieval Period, or at least, after the point when the Catholic Church established itself in the late-Antiquity, and before the Enlightenment.
It is easy to overstate the importance of early Christian texts. The early church was heavily fractured, with only a small set of core beliefs that were common throughout Christianity.
Once the Roman government got involved and the Church became more structured, starting roughly with the Council of Nicea (325), a standard doctrine and canon became prevalent that was HUGELY influential. That is not to say that other forms of belief didn't exist, but they tended to either get absorbed into the church or stamped out (see Aryan Heresy, for the most famous incidents).
Influential writers seemed to have no positive sense of Judas's actions - Augustine of Hippo wrote that Judas killing himself aggravated the guilt of his original sin - killing Christ.^1 This seemed to remain the prevalent view throughout the Medieval period - references to Judas are not that common, but when they do occur it is with a sense of sin and betrayal.
A great deal of the anti-Jewish animus in the Middle Ages was linked to the idea that Jews were responsible for killing Christ; Judas was often linked with Jews and his betrayal was seen as reflecting on them and Jewish character.^2
It's very hard to source a negation - to say that something did not exist, but I can say that Judas did not appear as a major issue in any council that I have ever read. The idea of Judas being pre-destined did not seem to be much discussed in Medieval period via the sources we have access to.
Judas's guilt becomes a matter of discussion again in the Early Modern period because of Protestant views on predestination. Martin Luther seemed to waffle on occasion as to whether or not Judas was to be condemned for his actions if they were willed by god.^3 Erasmus and John Calvin also wrote passages about the guilt of Judas, but I'm not an expert on this area so I'll leave that to others to pick up and discuss.
To summarize - in the Early Christian Church you'd be hard pressed to find an interpretation of events that someone didn't believed in; belief was very diverse. By the time the Catholic Church really gets going, there seems to be no indication of a major arguments towards Judas being anything but a traitor and a sinner. This line of thinking seemed to remain true throughout the middle ages, but in the early modern period thinkers began re-examining Judas in light of theology around predestination.
It's not a line of argument I've encountered, nor would it seem particularly agreeable to one of the core tenants of medieval theology. According to the canonical (or even the available) texts during the period in question, Judas' intent was unequivocally malicious, regardless of the final outcome. From at least Augustine (but probably from Tertullian or earlier), salvation centered around the act and the intent behind it, rather than the final outcome, and I cannot bring to mind a medieval theologian who proposed an alternate system. The main debate, centered on the question of predestination, was over the relative importance of action vs. intent and the role of divine grace therein.