Mr Woof spent about four hours last night running in and out stressed out and looking for me. He was very happy when I got home, and hopefully will be a bit more relaxed tonight. And hopefully I will be a bit more relaxed too, knowing he's ok.
The positive outcome is that he is now confidently using the dog door in both directions and no longer requires my dog door midwiffery to get up the courage to go through.
Miss Meow was also a bit stressed at having me out all night - she spend an hour or so in the early hours of the morning searching for me. Both of them were glued to my side in bed after I got home.