Quick update:
I was on Clermont Cairn a few weeks back and the site is still very much accessible. good few slopes in the area for easterlies most only suited for smaller gliders.
The Cairn itself is easily accessible and plenty of parking - looks like nearly all directions but N-NW have access to a usable slope although landing might be challenging.
Took a spin around and found amazing W facing slopes on the "Forest Drive" at Slieve Gullion. Wind was southernly when I was there which wasn't great but will certainly take a glider or two that way when we visit again.