In short, No, there is no “significant scholarly view (independent of arguments from the NT) that the book was written by a single individual.”
My source for such an assertive reply is Dr. Benjamin D. Sommer, Jewish Theological Seminary, New York (Ph.D. Religion/Biblical Studies, University of Chicago, 1994). The following notes are selected from his introduction and annotations for the Book of Isaiah in The Jewish Study Bible (Adele Berlin and Marc Zvi Brettler, eds.; Oxford University Press, 2004). I reference Dr. Sommer because his work is recent, and he not only follows the consensus of critical scholarship on the authorship issues – as opposed to a theological or idiosyncratic position – but at several points Sommer gives an indication of the relative strength of the consensus (e.g. some, many, most, or all scholars) which may address the OP’s concern about significant scholarship.
Sommer divides Isaiah into at least two major time periods – as do “all modern scholars” – and he credits most of the first part, ch.1-39, to the 8th century prophet Isaiah. His specific arguments can be found online, but his conclusions follow, in outline:
Ch.1-33: “Many modern scholars believe that large sections of Isaiah chs 1-33 were written by additional prophets and scribes who lived later than the historical Isaiah – that is, later than the 8th century. Others, including many leading Jewish biblical critics, attribute most or all of these chs to Isaiah himself.” The possible exceptions:
Ch.13: “This oracle assumes that Babylonia, rather than Assyria, is the world power. Hence it is addressed to an exilic audience in the mid-6th century, not to the 8th-century audience of Isaiah son of Amoz.”
Ch.24-27: “These chs share some features with later apocalyptic literature ... Consequently, many date chs 24-27 to the Persian or even the Hellenistic period. On the other hand, they also share many features with prophecies of Isaiah, such as the doctrine of the remnant and a thoroughgoing universalism. Whether these Isaianic features result from Isaiah's own authorship of these chs, and they should be considered protoapocalyptic, or from the influence of Isaiah's genuine writings on them cannot be determined, but most modern scholars opt for the latter explanation.”
Ch.30:18-26: “... similar in outlook and language to chs 24-27, and in all likelihood ... written in the postexilic era, several centuries after the life of Isaiah himself.”
Ch.34-35: “All modern scholars” date these chapters with ch.40-66 to a period after the 8th century.
Ch.36-39 “narrate certain events in which Isaiah played an important role. They were not written by Isaiah but are taken, in a modified form, from the book of Kings.”
Ch.40-66: “All modern scholars ... believe that chs 40-66 (and also 34-35) were composed during and after the Babylonian exile in the 6th century.”
Ch.54-66: “Many scholars believe that chs 56-66 or (more likely) 54-66 were written by yet another prophet, or perhaps a group of prophets, whom they call Trito-Isaiah or Third Isaiah. According to these scholars, Trito-Isaiah was a disciple of Deutero-Isaiah ...” Sommer outlines the reasons for thinking Deutero- and Trito-Isaiah the work of one author or many, but concludes “it seems clear that chs 34-35 and 40-66 as a whole are a single literary unit,” at least in their final composition.
And finally, on the Book of Isaiah in its current form:
“It is not clear to us when, or why, the prophecies of Deutero-Isaiah
were combined with those of Isaiah son of Amoz. The strong emphasis
in both literary corpora on God's universal kingship, the messianic
era, and the future exaltation of Zion may have suggested that these
texts belonged together. Already at the beginning of the 2nd century
BCE, the Jewish sage Ben Sirach ... knew a version of the book of
Isaiah that combined both blocks of material ... The great scroll of
Isaiah from the Dead Sea Scrolls (dating to the late 2nd century BCE)
also contains the entire book of Isaiah as we know it today.”