There is a reference to SAB closing at 6pm on the allears site, but it was during December, not October. I know when I was at BWV last month, and they were allowing BW guests to go to SAB (because of the Luna Park pool rehab) they were running the shuttles back and forth until 8pm. October is warm enough, and still light enough, that I would guess it would be open until at least 8pm, especially since that is a fairly busy time for the Epcot resorts (due to the F&W Festival).