Someone living 5+ years in a nursing home is the exception, not the rule. With that being said, it's possible it'll be you. The question you have to answer for yourself is, what amount of savings to cover that DOES make you comfortable?
Someone above mentioned they cost $140,000/year in their area. If they assume that as the cost, and worst case 10 years staying there, that's an extra $1.4 million they have to make to cover the risk. Is it worth it? Probably not for most people. Similarly, basing your plan on running out of money when you hit 79 years old and statistically die probably isn't a good idea either. There's somewhere in the middle that each person feels comfortable. If you live somewhere where nursing homes cost $140,000/year, consider moving once you have to go to a nursing home.
If you plan on preparing for every possible outlying situation, you're going to be working as long as humanly possible. Planning to work a bit in down years during ER seems like a good plan, and can make a big change to cFiresim predictions. The doom and gloom strategy of planning a 3% withdrawal rate and having a floor where you don't withdraw even 3% if investments go down and working in down years and having a supplement fund for healthcare and getting every type of insurance is probably overkill.
As for the OP, I don't think MMM is sweating 48k/year.