Mip mapping and texture sizes

I'm making some characters in zbrush and to capture all details, I need textures that are bigger than 2048 x 2048 pixels for a diffuse and a normal map. Since it could be, that there're more than 16 characters, I am not sure if this influences the performance because Mip-mapping reduces the texture size of an object when it is far away. So, does it matter if I use such large textures or not?