I think of it in terms of: if one of us spends say $500K (today's dollars) on LTC, is there still enough portfolio nest egg left over for the surviving spouse to have a decent quality of life? If yes, then the surviving spouse should also have enough leftover for their LTC if needed.
We don't keep it as a separate account, it's considered to be part of our retirement fund. And the simple assumption is that the surviving spouse won't need quite as much of a retirement nest egg as a couple does. Say, if a couple had a $2M nest egg that supported $80K annual withdrawal, and 1/4 of it went to long term care for one of the couple. Would it be reasonable for the surviving spouse to get by with 3/4 of the annual withdrawal or $60K? Maybe, maybe not - depends on the couple. I guess you have to figure out how bit the retirement fund needs to be.
BTW - I have heard numbers like $3M to $4M threshold nest egg for self-insure LTC. That would mean that after covering one spouse that say cost %500K, the surviving spouse would still have 83% to 87% of the portfolio which doesn't seem like that bad of a "paycut" for going from two people to one person living off the nest egg.
Wouldn't it be cheaper to buy LTC insurance? Maybe if it were absolutely guaranteed to be there when you needed it, and it were truly adequate inflation-adjusted coverage, and that you maintained it without interruption, and that you handled the increasing premiums over time. But some of us prefer to "take our chances" of not needing it, or not needing much, and if it turns out otherwise, well we better make sure our retirement fund is big enough to have enough left over for the surviving spouse. So then, if your retirement fund is big enough, why buy insurance? That's what it really comes down to.
It's when the retirement fund cannot survive the costs of LTC for one spouse without leaving the other destitute or in a very bad poor situation that you absolutely must buy the insurance.
Audrey