Wonderful stories! Thanks so much for sharing.
As much as I'd like to say that my dad had a comfortable exit, he didn't. So let me share a slightly different exit from earth. My mom had died and in the first months after, my dad tried hard to keep going. "Show me how to cook this dish." He got in a car accident, which scared him, so he quit driving and arranged with the local grocer to deliver food. He was doing laundry, etc. But, my dad also thought my mom had been murdered and someone had stolen her wallet. He was frustrated and angry, and spent time randomly dialing the phone to "talk to those detectives". He kept asking who was that old lady in the house who kept coming up from the basement (which we interpreted as his asking about where mom was). He'd angrily accuse me of thinking he was crazy when I'd talk to him on the phone. My guess is that most of his behavior was a combination of the grief over her recent death augmented by the stage of Alzheimer's he was in.
My mom had provided a lot of daily support for him and although my brother who lived close by did his best, we eventually arranged a patchwork of daily support for him. He adored the cleaning woman, and thank goodness for Meals on Wheels. My nephew took a sandwich over to his house almost every night to eat with his grandpa and they would watch sports on TV. But within about 8 months after my mom's death, we had to place him in a nursing home because he was sundowning, falling, leaving the stove on, becoming more and more incontinent, etc. He went willingly, but afterwards he withdrew from life, wouldn't talk to any of us, and was dead 3 months later after he contracted pneumonia (and we opted to not treat based on his wishes).
I think part of how one exits this earth is the reality of context. Maybe he would have had fewer problems and less mental stress if my mom hadn't recently died. But his final months were ones of anger and withdrawal. His world just spiraled out of control. As a friend of mine said, sometimes older couples travel in pairs - he died less than a year after my mom, struggling from a broken brain and certainly a broken heart.