An October use year will be the worst if "Fall" includes September. Its fine if Fall is always October and November. We like October, too, but now that our kids are out of elementary school and in middle and high school, its pretty much impossible to pull them for a Fall trip. Something to keep in mind.....Once they leave the house, then we will be free to travel whenever.
We have looked heavily Into both of your concerns.. 1st I'm a huge planner, like to have at least a 18 mo. to plan. Of course any trip that might get planned in the last 4 months of UY would have to be thought through and planned to the littlest detail.. (My specialty!)
Assuming my DH could get time in sept.
We do know the schools policies from elementary, middle and high school .. (And we do know they can change) Elementary they don't like them missing more then 8 school days in a row.. Middle and High school it's 5-6 And they are strict about it!! Sept. And May are pretty much off limits!
Also here is New England, we get a week off in February and in April (normally NOT Easter weekend) Even if we had to pull them out we would try back it up against one of their breaks, so they should only miss a few days.. Now we will still be on the same schedule when they got to college...
So we are looking at a min. Of 20 years before we are going to be able to travel in sept. (Youngest is only 2)
So let assume it's just DH and I, and we are going to go in sept. So if DH could get the time off, and we didn't mind going during hurricane season On top of that we normally have to get air fare.. (Haven't braved the 22 hour drive yet) So Any trip has to be WELL PLANNED in advance.. I could only see and act of god or a death in the family that would cancel our trip.. And at that time I would think losing a few points would be the least of our worries.
But I do understand what you are saying about travel in sept. After children leave.
And we may look at a sept or aug use years.. If the price is right. But OCT is our 1st choice..