100 BTC could take care of the full money supply of an entire country if it got popular enough. Easily.
Please give a thoughtful answer, you did not answer what would happen after btc supply stopped expanding, yes price would rise, btc would become divisible and only a few would have whole btc. What stops the economy from becoming lopsidedly deflationary?
We don't need to stop that. Seeing as we'll hit the cap over a hundred years in the future, likely by then Gaven will have put in a change to sort this problem out(ex. adding 8 more decimal places) or Bitcoin will be overthrown and replaced with something better. Hey, will any of us live to see a single Satoshi having accountable value?