Hi, just for info, the annual Longmynd Hike takes place over the weekend of 6th and 7th October,details here http://www.longmyndhike.org.uk/.
It includes SOTA summits Longmynd, Stiperstones, Corndon and Caradoc, and probably a few Humps inbetween.
Activations would not be impossible, but there are around 500 walkers, so the area is quite busy from around Midday on the Saturday until midday on Sunday.