Well as crazy as it is, North Scotland is still somewhat south to us.. of course due to the ocean it isn't warm in there, but at least you have a bit more light than we do :) Six hours is far too little to keep your body working properly. The darkness can give you power in it's own way, but I'd still be happy to have at least 10 hours of daylight before the darkness strikes!
There are also these wake up lights you talked about. Haven't got one yet, but I've heard they are usually really handy. It's just a shame we wake up so different times with my wife, so I couldn't really use one without upsetting her. (or moving to another room)
I'm taking vitamin D, I've lack of vitamin D can cause depression (or depression symptoms) but that it wouldn't help specifically against SAD. But I assume it's always a bit of an mystery, but so far the vitamin D has not helped me at all :) But I'm glad you can enjoy your mushrooms!