It makes absolutely no difference where an incident reading is taken. The only thing that matters is that the meter sees the same light as the subject does, and with the same orientation relative to the source and camera (angle of incidence).
I.e. if the light source is the sun behind you and you want to take a picture of a mountain 3 miles away; then just point the meter towards the sun (as if it were the mountain looking back towards the camera).
If the light where you are is different than it is at the subject (i.e. you're standing in shade) then the meter needs to be relocated to where it is the same.
Edited to add oversimplified drawing to help explain situations mentioned in the comments.
The closer a directional light source is to the subject, the closer to the subject the light meter must be placed in order to have the same angle of incidence and to account for light falloff.