Yep, 5 days later and my parents are still with us. My brother has phoned a couple of times from Australia and on both occasions he has greeted me with "Hi, is that Sangatte Refugee Camp?"
Mum and Dad's flights on Wednesday were also cancelled, although at least this time it happened before they left for the airport so they didn't end up stranded on a snowy kerbside with their suitcases. They are re-re-booked to leave on Monday, a week later than originally planned, but better than nothing. We are not predicted to have any more snow before then, so the signs are looking good. (They had better get away on Monday: we learned today that their neighbours in Livingston, believing they were away in Australia for 5 weeks, have used their driveway as a repository for all the snow they've cleared from the road. The pile is about 5 feet high. Oh, and the water has gone off for some reason in the entire estate. So there's that.)
Also, my sister-in-law was supposed to fly to Schiphol today and from there to Kuala Lumpur on business and she too has been cancelled due to snow in Holland. Fortunately we had driven her to the airport and were able to turn back and collect her and bring her home. She has been re-booked for tomorrow. Our free Edinburgh Airport shuttle business is working well.
I think the gist of this post is: Britain does not cope well with bad weather. The End.