They are a full-time care giver to their wife.

He can hire someone to do that for far less than his 100k salary (even after taxes). There are possibly further issues that OP left out of his post but as written it is a bit confusing.

FWIW, they'll have to coordinate this after a new job since there isn't one at all providing for the household, which may or may not be easily attainable considering the FT care provider situation (and assuming the worst as far as how much attention/care is required throughout the day).

Ya, that's definitely true. And the issues there can vary A LOT depending on where OP lives. It can be a tremendous amount of work to manage these sorts of situations.

(I spent two years working for a home care company.)

Not in an area that gives you a 100k salary. And any kind of 'household employee' you hire will be after tax income.

There might be some tax deduction when it's medical reasons, but I'm not sure about that.