I rescued a senior Golden for my father. Senior dog with a lot of medical problems. Vet knew I was looking for a older dog for my late father. Called and said he had a dog which the family was going to put to sleep because they did not want to bother with complex medical problems but would let him be adopted instead. So you know I went and got him. My father had a bad habit of pampering his dogs until they were happy, fat dogs, who thought he was the greatest thing since dog bones. This golden was nine at the time we got him. He lasted until he was 13 and gained about 35 extra pounds. He did not die from Addison and outlasted all but one of his Golden's. So Addison is something you can deal with. We did have to watch for stress ut I am sure you already knew this.
We managed the same condition in my brother in law for almost 30 years. He is dong well except for a near terminal case of stupid, married to another case of stupid. Last I was told he and his wife were Druids or Wiccans who were going totally organic vegan and thinking about living off the grid. Yeah, thank God they are family by marriage and those genes will end with them. And surprise they voted for Biden. Hope your dog does not vote for Joe as well.