A good deal of it would depend on whether or not you own a house. Many retirees do. $550,000 invested prudently should produce $44,000/year (8%). If we assume taxes are about 33%, that's $14,500 in taxes to be paid (keep in mind that this will not be "income" for tax purposes but capital gain. If you work it right, it'll be a long-term capital gain and only taxed at 20% and with deductions and exemptions and all that, 33% is a pesimistic estimate of tax.). That leaves $29,000. But, retirement is a long-term thing -- usually -- so you need to re-invest about 1/3 of that so that your earnings will grow to keep up with inflation. That leaves you just shy of $20,000/year in spending money. That's about $1650/month. That may not sound like much, but if you're housing costs are only property tax, insurance, and maintenace (which could be around $500/month), then you've got $1150 a month of disposable income. That is livable.
If you're over 55 1/2 years old, then you can add on some social security to that figure.
Basically, you could live modestly but comfortably.
On the other hand, if you don't own a home and have to rent, it's gonna be tough.
Let's say you go into this retirement with $550,000 cash and no home. Should you buy a home? It depends on how long you intend to live. If you intend to keep kicking for more than about ten years, then you should probably buy a house. But not a $200,000. Nope. $125,000 max. That leaves $425,000 to invest at eight percent producing $34,000/year. Take out 33% for tax. Reinvest 33% of what survives taxes. Allow $300/month for property tax, insurance, and house maintenace. And you end up living on about $972/month. That's tight. But, housing is already taken out of that, so that's no an unlivable sum. And, again, if you can throw some social security into the pot, you'll be ok. And if you can manage a bit of side income -- especially if you can do it in cash and not pay tax on it -- you can get along.
It will depend a great deal on where you want to live too. According to the National Cost of Living Index, $30,000/year in Buffalo, NY -- a perfectly nice city --is only worth about $11,500/year in New York City.
So, yes, I think that a person in good health could retire very modestly -- but comfortably -- on $550,000.