My uncle made it, from 2015 to 2022, on disability (switched to regular SS at age 65 I think? At least I remember his payment going down), and an inheritance from Grandmom.
His last SS payment was around $1740. When Grandmom died, I think he got about $120,000. He was living in Grandmom's house, helping take care of her, and he stayed on after she died. So he didn't have a mortgage, but he had upkeep on the house, utilities, property taxes, insurance, etc. The house has oil heat, and it's the type that runs all year long, because it heats the water as well, so it can get expensive.
Among the financial highlights I remember, were him buying a new 2016 Chevy Colorado that was around $29,000. He traded a 2013 Camry on it. I don't know how much of a trade he got, though. In 2019, he bought a used 2006 Sienna minivan, because he wanted something that he could, in his words "drive the family around" if needed. What prompted this, was my great-aunt went into the hospital at the age of 96. He took his cousin (her daughter), and another relative, who was 94, to the hospital, and it was an extremely tight squeeze in that truck, so he wanted something that could seat more than a driver and one passenger with relative comfort.
I told him, "what family? Our family is dying off!" But, he wanted the thing, and bought it. And sure enough, my great aunt died like a few weeks later. The 94 year old cousin made it to 95, but died at the end of 2019. And the other cousin, who was in her 70's, moved to Florida soon after her Mom died.
Anyway, between the purchase price, and what he put into the minivan in repairs, it was probably around $10-12K.
By late 2022, he was getting to the point that he'd have to start getting into his IRA. But then, we sold the old family homestead across the street from Grandmom, of which he got half. I figured that would be enough to keep him flush for the rest of his life, and by the time he had to start doing RMDs on the IRA at 73, in 2025, that would just be icing on the cake.
So, in my uncle's case, I'd estimate he blew through $120K in about 7 1/2 years, plus his SS. So, for his lifestyle, I'd say around $3,000/mo, or $36K per year, as a VERY rough estimate. Considering there was a new truck, and a minivan he didn't need thrown into that mix, I think he did fairly well.
He pretty much kept to himself, although he'd go to various family functions, come over to see me, go down to Southern MD to see my Mom, etc. He tended to eat out a lot, too. Mostly fast food, but sometimes he'd splurge on Denny's or Bob Evans.