Reagan was already ahead in most polls post-convention save for September. 
By 10 points? If you research, you'll find the answer is a big "no, not even close".
Almost every single poll (even October polls!) had Carter and Reagan well within their margin of error. Read what Caddell (Carter) and Wirthin (Reagan) said about their internal polling also. They both had it as too close to call until after the last week debate.
There was a late break for Reagan in 1980. Many polls did not capture that. Precious few did. And those that did, did not capture the magnitude of that break.
That was a less polarized era, and given the way demographics are, such a thing would favor Clinton anyway since trump's insulted literally everyone.
It would literally take Kentucky 2015 turnout for your theory to play out.
