I'm not sure what you mean? what are you referring to when you say size?
Electrons have a local volume of space over which they exert forces, non uniformly with increasing magnitude. Attempting to restrict the volume of space an electron can exist in increases the magnitude of these forces.
Size to me is a classical scale approximation, like temperature or state of matter. Electrons aren't distinct subatomically in not have precisely defined boundaries of interaction so I am confused about whether you mean something else.