Do all our MSS go back to a single error-ridden copy?

This is germane to Bart Ehrman's wildly unrealistic hypothetical (which he never documents, that I'm aware of) that all our extant Greek MSS might go back to a single error-ridden copy. 

Trobisch attempts to circumvent the major crux of the issue by positing that seeking the original text is not about the individual books or their MSS so much as about the canonical text. As he states, "The history of the NT is the history of an edition, a book that has been published and edited by a specific group of editors, at a specific place, and at a specific time." He places this edition in the late 2C. As a result, one is seeking not the original text, but rather the original canonical edition, from which the later MSS can be traced as derivative. As interesting as canonical development may be, this too is not a solution to the question of the original text, as it begs the question of the prehistory of any book before it was 'canonized' and instead concentrates on the ordering and features of MSS that indicate their later editing, Stanley Porter, How We Got the New Testament: Text, Transmission, Translation (Baker 2013), 28.