bookworm, I take it all back and bow to your greater breadth of reading.
As far as I am aware there are no local ATC procedures in the UK in which temperature corrections are applied - I stand to be corrected, perhaps from someone working at one of the northern Scottish airports. Certainly those I've worked at in southern Scotland (albeit it was a good few years ago now) did not apply any corrections and I recall a good many rather chilly nights! I trotted out what I understood to be the UK policy following a brief flirtation on the topic a few years ago. Maybe I misunderstood the discussion????? Maybe procedures are designed with corrections for the 'UK worst case' already applied (although the levels in procedures do not suggest this is the case)?
As you point out the difference can be significant, even in the UK's temperate climate. The AIP does not indicate that the UK has filed a Difference for the application of temperature corrections so, in theory anyway, the corrections should be applied somewhere.
As an aside, the UK is subject to an ICAO USOAP audit in the next couple of months - it will be interesting to see whether this topic is picked up. Actually, it will be interesting to see all the topics that are picked up....