Fixed that for you.  If every single BTC already mined was lost today, the currency would still work just fine.  In 200 years, long after the subsidy was done, even if only a single satoshi remained, the currency would still work.

Bitcoin uses a scaled integer representation.  We can change the scale factor to renormalize, if needed.  We will almost certainly do it to match future CPUs many decades before we need to do it for economic reasons.