Thank you all for your concern.
I locked the top lock, which cannot be opened from outside, and brought the dog and DS into the master bedroom and locked that door too.
Managed to get a few hours of sleep.
Don't know anything new. I assume that if he got picked up, someone would have called me by now... but you never know. He probably got to wherever he was headed.
I'll be suprised if he's not there when I get home, but I guess we'll see. I hope not. It would be nice to have a peaceful evening with DS.