If one wants to add a new receptacle on the second floor in a finished room with no receptacles, the easiest method appears to be doing the wiring in the attic.
However, this would require one to drill one hole through the top plate, in order to get the wire from the desired receptacle location into the attic.
This still beats the only other method to add a new receptacle, which would require one to drill multiple holes in multiple studs, until one reaches the desired receptacle location.
How can you determine if a top plate is load-bearing?
If it is, what are guidelines to bear in mind, in terms of the location of the hole and the maximum size of the hole that can be drilled, without requiring additional structural blocking?