John, welcome to WhitneyZone!
I hope you get some takers for October.
You should know, though... that is pretty late in the year, with less daylight and more darkness, plus you run the risk of snow arriving before or during your visit.
Are you picking October because you have a permit for that time? If so, I hope you are aware that there are lots of no-show permits available especially the last half of September. Check the
Unused Permits 2010 page to see what was left AFTER all the walk-ins were accommodated.