It is not a mathematical question, but why they are thinking about retirement when: 1) they still have a mortgage, 2) they are not a retirement age people? The correct question would be: 1) Can I retire with $863 - $202 = $661k? and 2) Can I retire 7 years earlier?

Fully depends on where you retire!

IMO this 60 year old person should compromise and work until 65 to minimize expenses, get to Medicare and let their Social Security grow that much more. Even better is Full Retirement Age of 66-67. I did not collect SS until 70 and it was one of the few good financial decisions of my adult life but that is not for everyone. I salute all who can retire this early, but it is not wise for everyone.

What about Roth conversions? Would that help?

I am a 55-year old burnt-out doctor planning retirement soon. Currently seeking best strategies for market downturns and hyperinflations to save my $400K declining portfolio

What jumped out at me was their health insurance cost is ridiculous, I am guessing they plan on private insurance. Also, all of their savings is in a tax deferred account, thus they have a high tax liability. If they are able to reduce expenses far enough to qualify for ACA, I suspect it would make a significant impact several ways.

Because you can't afford to retire. Geez.