There is a little more to cabin temp control than has been previously mentioned. I recommend that next time you have a long flight, especially at night, you opt for centre seating, on the 767 at least. Stay away from the sidewalls!
I can offer this info based on my experience with B762's. during cruise I used to run the mid and aft zones at 22 - 23 indicated initially then try to get the aft zone up to 24 when all down the back were supposed to be asleep. A quirk of the system on some aircraft (later, not earlier models) is such that the only way to increase the pack outlet temp when cold soaked is to crank up the cockpit temp and thus increase pack outlet temps which in turn gives warmer air down the back. Sometimes, heaven forbid, even "MANUAL" has to be used in lieu of "AUTO"! As a bonus though it means better cockpit service 'cause it is much warmer than the fwd galley and FA seating. The descent cabin temp control? Now there is a challenge! Anybody remember how well it all worked before that inflight low idle mod? Before everybody jumps in here with their own theories, we had access to the ECS page, on ground and inflight. That lets the cat out of the bag to those in the know! :-)
Just to sidetrack for a moment, years ago I had the experience of doing a few sectors with Boeing contract boffins on board who were troubleshooting an on-going random pack trip problem and I can tell you now that there is a lot more to the way the system operates than what's stated in the pilot's operating manual and maintenance manuals. Delve into the pack controllers etc and you will see what I mean. (FYI, a wire trace found that somebody had drilled through a loom!)
Go for it Ted!
Cheers.