For example my house is paid off. My total yearly spending comes out to under $25k/year. That omits irregular things like the occasional need to replace a broken appliance, or upgrade to a new computer/phone/tablet/watch, or get a new car.

Looking at how often those irregular things happen and how much they cost, another $7k a year reserved for that would be sufficient, assuming in any years where that is not spent the left over is carried forward.

That's $32k/year income needed to live comfortably in my house. My house is worth a little less than half a million according to Zillow. I'd guess a million dollar house would cost about twice as much to insure, and is bigger so costs more to heat or cool. Assuming 2x insurance and 2x electricity costs would add another $3k, suggesting $35k/year income needed for a million dollar house, at least if my standard of living is acceptable.