Is this morally justified in your opinion?

[Bojack Horseman]

This is hypothetical, but based on events in my family.

You and your spouse have been married for a few years. Your mother in law comes to visit, and while at your house, she has a stroke. Your spouse promised her a while ago that he/she would never put her in a nursing home, no matter how much she needs it. Four strokes and a diagnosis of Lewy Body Dementia later, he still refuses to put her in a nursing home, even though her care is becoming more and more exhausting and extensive, it's putting a drain on your finances, and you're worried about all the strange nurses coming in and out of the house at all hours of the day.

Is it justified to say, "Either put her in a nursing home, or I'm leaving."