I think for this game the player count has more to do with the size of the map. The game might be too easy with 5 players when there's a total of 36 locations (I think). It might work though. Maybe someone who owns the game can give 5 players a shot.
I think there are 24 locations (6 in each town), which is half of regular pandemic. But original Pandemic has 48 player cards. PRoC has 44 clue cards, and sets difficult not by increasing the number of evil stirs, like original pandemic, but by decreasing the number of player turnos with fewer clube cards at the deck