In reply to Seb Lee: Hey there
You're nearly out of time for December!
I don't usually give as much attention to bottoms as tops. In winter it's a pair of thermals I picked up for cheap, maybe a pair of trousers for extra warmth and Berghaus Deluge waterproofs over the tops - which in my experience have always been great. They seem to be popular as well. Get them in a short leg size though, I find the normal length wayy too long and I'm of pretty average proportions.
All in all as long as there's something waterproof on my legs I think more about my core, head and hands.
Camping in the glen: the no camping signs are there but get a secluded corner and you'll be fine in December. I'd only give it two thoughts in summer when I'm sure the residents have had their fair share of problems from irresponsible camping (this is a guess but not hard to imagine)
Navigation: long as you're aware of the navigational problems getting off the plateau in winter. In calm winter conditions it can be easy with a path beat into the snow. In bad conditions be really careful.
Have a good'yin