In 1980, there were 158 electoral votes which might have flipped to Carter if he could have added all or nearly all the John Anderson votes, the green states in this graphic.
Those in the south probably would not have been among them since the combined total would've been such a narrow margin over Reagan, it is unrealistic to think they might have flipped.
But even in this case, Reagan still would have won an impressive 331 electoral votes.
Nice work.