I'm sorry for your loss bbinder. Our family went through a similar experience a little over six years ago with our beloved golden retriever Tucker. We were fortunate enough to have our vet come to our house as well . I didn't want him to die alone and per your experience he greeted the vet when she arrived. It was a tough experience for everybody for sure.
I let my wife and daughter decide if they wanted to get another dog and about a year or so later the opportunity presented itself and we were proud owners of another golden retriever. This time a female; Sydney. I quickly learned all dogs are different as Tucker never barked and Sydney's favorite past time is to sit at the window and bark at what is going on outside. Tucker accompanied my wife everyday to he store where he would greet customers and lie back down after they patted his head. Tucker was extremely "laid back" and mellow.
Sydney on the other hand gets excited around people and I did a lousy job of breaking her of this. As a result, Sydney has become pretty much "my dog" spending everyday I am home with me at my office under my desk. She's the best jogging partner I could possibly have, every morning starting at about 5:45 AM she makes sure I am getting up so we can get to the trail we go to. (Yes we made the mistake of letting her sleep on top of the bed with us).
Sydney is now 5 and as Tucker was a bonafide member of our family. Dogs are great and unfortunately their lives are too short. The best consolance that helped me was knowing that when Tucker was with us, he never had a bad day. I'm sure that applied for your Cuppago too.