for info on motor lead length, do a search for Bob Boucher (Google or RCU, RCG). There was a discussion of this recently on one or the other of those sites. As the "Father of electric flight" (Roland might argue with that), I think he's about as expert an expert as you can get.

Essence of the article was that esc to motor wires can be as long as you want providing they are of appropriate gauge to overcome resistance.
Walt