I can't find any information on that. In northeastern states like Connecticut, they would've had to break for Reagan, but in Midwest farming states like Iowa, they would've had to break towards Mondale.
Anderson himself endorsed Mondale IIRC. According to one poll, Anderson's 1980 voters voted Mondale by a 68% - 29% margin, virtually the same as Carter's 1980 voters (73% - 26%).
It's instructive to look at some of the most liberal cities/towns in MA, Anderson's best state:
Cambridge: 1980, 60.8% D - 19.9% R; 1984, 76.2% D - 23.4% R.
Brookline: 1980, 50.6% D - 30.4% R; 1984, 69.2% D - 30.7% R.
Newton: 1980, 45.8% D - 35.4% R; 1984, 62.7% D - 37.1% R.
Clearly Mondale got the lion's share of the Anderson 1980 vote in these places.
Surprising margins; it makes it hard to believe Reagan could squeeze enough votes to win '76 Ford/'80 Carter counties like Monroe County NY, Niagara County NY, and Grand Isle County VT.