In reply to nickcj:
> Have you considered Paramo. They do a 'medium-long' fit which could work.
Or, I think, the women's trousers (but maybe they don't do women's salopettes?) in a long leg length - I'm 5ft 8/size 10-12 and the women's small fit OK in standard length, so long leg would probably be OK. (The men's small also fits me OKish). Agree they're a good option if you don't want to swap layers.
Equally, if I expect to wear over trousers for the bulk of the day, wearing stretchy layers underneath works well - eg walk in in thin base layer and hard shell trousers, and add a powerstretch tight in between for climbing. Clearly not ideal to strip off your shell (and, more awkward, boots) if conditions are properly Scottish, but can work., and you're likely going to stop somewhere to to put harness on, etc. I get cold quite easily, so tend to prefer having plenty of insulation if there's likely to be any standing about....