Conundrum…Explain my wife's behavior in social situations or not?

I have found these cards to be most helpful, particularly when dining out and traveling (both of which are becoming less frequent now!).
Lots of thumbs up, smiles, and thank yous.

Rather than asking people on this web site your questions, I would suggest asking your wife. If she has MCI, then she knows her condition (and her family's history) and can direct you how she wants you to handle the various situations. It's good to know her wishes now before she progresses. If people don't want to know or in denial, then forget about them and focus on the most important person, your wife.
My wife goes out on "dates" with our son and grandkids (individually) and has frank conversations with them about her condition (she has moved from MCI to dementia) because genetically it's important for them to know. My wife's mother died from Alzheimer's so it is running in the family.

@randywhite I will bow out of this thread, but not before stating one thing. My personal, firsthand experience is that grief and how one grieves are among the most personal and highly individualized emotions/experiences anyone lives through. I deeply believe there is no mathematical equation for "proper" grieving, nor standard steps as are so often written about. Just as our love for someone is our unique experience, so is our grief when we lose them. Judging someone else's grief can cause unfortunate hurt and, again in my experience, does nothing to help that person with their grief.

Hi @randywhite, My husband has moderate Alzheimer's Disease. He was diagnosed in 2019, but I knew things were amiss in 2017. The Alzheimer's has made my husband less sociable. He doesn't care to leave our house much so I shop, bank, and run errands alone. When friends come to the house, he's usually standoffish and stays in his room. I've found that coaching him in advance regarding acceptable behaviors sometimes helps him. At other times, he forgets. I try to protect him and only tell others of his condition on a need to know basis. I've told relatives and close friends, a couple of neighbors. For more causual acquaintances, it depends. I disclose if the benefit of their knowing would outweigh the risk of their knowing and would not subject him to ridicule or harm as far as I can know. I also tell people who expect me to be more sociable of his condition to explain why I decline invitations.

Thank you for your thoughtful, considered sentiments. 🙏🏻. You have observed, and tentatively speculated with insights.
Regarding our approach to this challenge; one colleague when I worked said ‘the enemy of courage is fear’.
There is also a relationship between denial, reaction, and results:
No denial>acceptance>determined action>advancements (for MCI=Pace reduction and impact abatements)
Denial>complacency (surrender)>unabated decline
My goodness, it’s not like we are helpless & MUST surrender. But nor is it like we can Control the situation either. We are like riders on a horse, if we surrender our will, the horses wanders where it wants. If we exercise will via the reigns, the horse goes where we wish. But in spite of what we wish, it cannot fly. Only pigs can fly.🤣
And we are gratified to have flown to great heights, on wings of eagles Isaiah 40:31