To be frank, if your father has Alzheimers and you're thinking about a revised portfolio that is 50% cash equivalents and only 20% in equities, I believe he needs a professional adviser. If you really mean cash and short maturity instruments like money market accounts and CDs, they are apt not to keep up with inflation.  That $50K is only the current care cost hurdle, which is certain to grow and likely  faster than inflation.

There are lots of risks and being too conservative is one of them.  The house is a disposable asset which can best be dealt with by the trustee or POA when the time is appropriate.

 I am in your Father's age group and am convinced that a properly diversified  portfolio can achieve a risk-adjusted  annualized total return of at least 8% over time.  Given the actuarial realities, your Father's net assets should prove adequate.  Going heavy to cash will make it harder.

I think you can accomplish this ROI or better by selecting a few good equity and bond  funds, plus cash management to meet current  expenses, thereby saving the $8K in broker fees. It would certainly be worth a one-time fee to first consult a professional adviser.  JMO and good luck