In reply to David Kirsfelds: Can't say anything about that bag specifically but the ME bag I tested last winter
http://www.ukclimbing.com/gear/review.php?id=5328 seemed really long to me compared to other brands. For example Marmot say their standard bags fit up to 6 foot, so 183 cms and the ME bag looks laid down on the floor 10 cms longer than the Marmot bag I have. So I think you'll be OK if you are 185 and the bag says fits to 185.
Best thing of course is go to a shop and lie in one! Or at least pick an internet shop where returns and swaps aren't too expensive.
I've found the comfort limit ratings now used with CE standard very good, so if ME says the bag you're interested in is good to -12, then I'd trust it to that. I would imagine for scottish winter nights that's plenty particularly if you're bothying.