He currently lives in assisted living in an apartment. He pretty much needs directions on what and when to do things. He is also using up his savings quickly. My son offered to have him stay as a tenant at his home and have assistance for daily activities while he works but it will cost mostly the same amount. I'm conflicted on whether or not to take him up on his offer. I like the fact that my dad would be with family but then what happens when the Alzheimer's takes over? I live out of state and no hospital close by.
If you are concerned about his financial resources, I'd consult with an expert on how that works in his state to get info on what to expect. Often Elder Law attorneys may be able to assist.
Even if your son had a caregiver during the day, someone would need to be awake at night to watch over your Dad. That would mean your Son would need to sleep with one eye and ear opened listening for his Grandfather. Some elders will have a phase where they would open the front door in the middle of the night and wander outside. Alarms would just frighten the whole household and your Dad. And you can't lock Dad in his bedroom.
I remember when my Dad, who was 94, moved into senior living and later into Assisted Living/Memory Care, one thing he liked was being around people of his own generation. Plus I knew the building was secure after hours so Dad wouldn't be able to get outside.
When around-the-clock supervision is needed and outside help must be hired, it is almost always more economical to use a care center. They have economy of scale on their side! In addition to hiring care while Son is at work, someone would also need to be hired everytime Son wants to hang out with his buddies, or golf, or attend an evening work event. It adds up. So I would not recommend this as a way to make funds go farther.
This would definitely not be a traditional landlord/tenant relationship. Has your son ever spent an entire day at the ALF with his grandfather? Does he really know what it is like to be with someone around the clock who has dementia?
There are certainly nice aspects to care by family members. And there are advantages to a professional setting, too. Does your son live close to the assisted living facility so that he could visit often? Have Sunday breakfast with Grampa, and play cards with him Wednesday evenings? This would be an attempt to blend the best of both professional and family care. I think that the benefits of family care are most applicable in the early stages of care. Especially with dementia the more advanced stages are harder to manage in a private home with only one person on site.
It sounds like you father is needing more care. Maybe the next step is paying for additional care in the ALF, or going to memory care, or perhaps a nursing home. How is he doing in the ALF? Does he like it? How long has he been there? Other than the cost, are there specific problems or shortcomings you'd like to see remedied?
I hope you leave your dad in his assisted living and encourage your son to spend time with him there.