I have been researching an article on Condo cruise ships, there are currently two new ones being built, and a third which is an older ship that is being purchased for renewal (but this out fit sounds a little shaky).
It is not cheap, and the medical care is not included, but it could be done.
BTW: the famoud ship reitree ever, Rosemary Roberts, is a legend in the industry. She lived on Royal Viking ships for several (four or five) years.
I knew her, she was on one of my ships. She acted like one of the crew, not a passenger. She would sit in the main lounge/sun room (kind of like the old Westerdam's Queen Anne's room) and knit all day. When waiters would set up the buffets she would tell them when they had the placements wrong.