Halloween Time will be long gone by your trip, and the holiday decorations should be going up, if not mostly all in place in the parks (but not the hotels). Haunted Mansion Holiday always starts when Halloween Time begins and lasts until early January, so it will be open during your dates.
It's a Small World Holiday -- if it sticks to tradition -- will probably soft open on 11/6 or shortly thereafter. Again, this is assuming that nothing changes in the schedule due to the current 60th anniversary events (which are due to last all year long). If the 60th's events don't impact IASWH, then expect the soft open on the weekend I mentioned. If IASWH is delayed, for any reason, it might open just before Veterans Day.
I don't think the holiday season will have officially begun until at least 11/12, if not a few days later. It never officially begins on or before Veterans Day anymore, but all of the in-park decorations and some of the entertainment are usually in place (in an "unofficial" capacity) by the weekend before Veterans Day, as there will be some sort of footage taped for ABC on that weekend and the parks need to look somewhat festive (usually it is the Christmas parade that's taped; this year it will be something else and not the parade).
This year there are many questions about what will happen during both Halloween Time and the Holidays, and when/if it will happen, as the main focus at DLR seems to be on the Diamond Anniversary celebration.
Thanks so much 
