Just to be clear. there is never enough current in an interconnect to heat it up and change its electrical properties.
Same with speaker wires unless they are drastically undersized.
Thermal changes with power are much more likely to occur in your amp.
The article above is specific to voice coils which can heat up with high power (near rated power). So I'm driving a pair of speakers with 800 wpc power handling with a 10 wpc amp. I think I'll be ok.
Jerry