I know how that situation can be. My younger GSP ran off chasing deer one night when my dad was letting them out for their nightly exercise. Got a call from him after I had driven 2 hours back up to school saying he had run off. I told them to keep looking for him and called several friends back at home. One of them saw him near a busy highway and eventually my parents saw him but he was too scared to come him. Anyways, I left for home at 4 am (after only 2 hours of sleep) and drove around a bit. Saw a few people out walking and made some contacts with them. Eventually it paid off with the contacts and we found him trotting down a country road, exhausted.

So my advice to you is to actually go door to door around the area you lost him and around the area you think the dog might be. Make some contacts with the people and show them PICTURES of the dog and give them your phone number. Best of luck to you!!!