For one thing, every printer is different. A given thermistor reading might men different things for the print surface depending on placement of the thermistor and the construction of the bed.
All the temperatures you list, if taken as actual print surface temperatures, are too hot for PLA. It is generally regarded you don't want to go over the glass transition temperature of the material, which for PLA is typically 60-65 C.
Directly answering the question, for any given lot of any given material printing on any given print surface with any given surface prep, making any given part configuration, there's a range of temperatures at the critical locations on the bed that will provide adequate adhesion. For some parts on some machines on some locations on the bed you might have to offset your normal bed temperatures in either direction to keep the critical locations in a usable range.
