I'm gonna say "no problem"... I tend to think that while wiring "just so" is great as insurance and there's no harm in it, there's a lot of overkill out there in the standard wiring recommendations.
I say that because as construction continues on my new layout, I have run the DCC bus, but not yet gone around and hooked up the feeders. So I'm running the entire thing (300+ feet of mainline, plus 300+ feet of logging branch, plus various sidings, etc.) through a single pair of 22 gauge feeders about 48" long from the command station to the track. And it runs fine.
Obviously I will drop feeders to the bus at regular intervals on the 'better safe than sorry' theory. But I'm surely not going to worry about whether they're 6" (or even 12" long) given the current situation.
Kris