I think what you're getting at is that at some point the USD will be utterly worthless, the printer will stop, and so BTC will no longer even be priced in USD...is that close?

But Bitcoin doesn't go to zero when the USD does, it just gets priced relative to something else. Hopefully that something else is not some other fiat currency. At that point the market simply takes over and 1 BTC = [whatever someone else wants less than they want 1 BTC]. I think I'm saying the same thing you are in different words...