Personally, I think a million is enough to retire on, but only because I don't have to support any kids or anything, and because I don't have expensive tastes, and because I'm really, really good with money. Most people can't believe I live on the income I do.
After paying the taxes off, I'd invest it. I'd try to live as cheaply as possible in the meantime, and probably work at least another year so that I could live off my current income and let all the after-tax million do its work -- because then I can start living off the income from it, and still have some to spare to keep investing. And then later when it's worth more, I can relax and start doing more fun things, like traveling. Don't know if I'd buy a bigger house, but I might get a different one, but really, I just moved and hate to do it again. LOL.
I wouldn't, however, expect to be rich unless I invested really well. I'd hope, but wouldn't count on it. But I don't need to be rich, just more comfortable that I'm OK with money.