MtMikeR, you are certainly planning enough time for your trip. The main drawback for October is the threat of weather. The first snows of winter usually come in October, so the weather will dictate how it well it goes. It could be dry and cold, or it could be cold and tramping through snow.
The other issue is the length of darkness. Sunrise 10/1 is 6:48am, sunset 6:37 pm. In my opinion, trying to get an earlier trip date would be well worth it.
