IIRC a lot of people thought 1980 would be a lot closer than it actually turned out to be, so probably two or three states there. Arkansas is certainly one that comes to mind.
A lot of them actually. IIRC, I found a copy of Time's map from the week before the election in which Alabama and North Carolina were both Safe Carter and much of the rest of the South was Lean Carter.
While their margins were off, Reagan's worst region was easily the South, and he barely won most of those states. I wouldn't be surprised if pundits underestimated the growing suburban vote in the South, which accounted for almost all of Reagan's strength and certainly his margin of victory.