We were in exactly the same situation with our old girl....RIP...but she also had cancer...PTS was a very difficult decision to make. We moved to a remote Qld town, which only had a visiting vet every 3 weeks so couldn't risk taking an older sick dog. I know crazywhips personally and I'm certain that they would be making a very educated decision when it comes to their dogs.
Good luck - which ever way you make your mind up it's not easy.