A lady I knew (who did not have dementia) went into care. She had willed her house to a relative and was upset that this would not happen if the house had to be used to pay for her care.
Luckily, the relative concerned was able to raise the money to buy the house, at the market price, and the LA was happy with that as the lady then had the funds to use for payment.
So, Grandson, it doesn't have to be all sorted out ahead of time. If you may be able to buy the house, you can deal with that when it is necessary.
Please try not to take offence, we know nothing about you, after all, and people are bound to look at things from all angles.
Parents-in-Law. What do/did you call them?