Hello spark and welcome to the forum.
To answer your question, it depends...
- You say you live well below your means, but what annual income do you need to live the way you want to live in retirement? Once you have that number, run it through FIRECalc http://www.fireseeker.com/
and see what it tells you.
- The other big "depend" is health care. What are your plans to secure health insurance until you and your spouse qualify for Medicare?
Looking at your total assets, no mortgage and a reasonable living expenses, I'd say you are very likely well within coffee sniffing territory.