Grade school geography class? There’s many enclaves all over the world already, just not in this concept.
Discussion
You may be surprised. An enclave as you describe or similar (not necessarily btc based) are being planned. I think Chaumian Mints might be a useful idea for a community such as this as a bank type role based on BTC. Also I imagine the powers that be would love to derail it. I think the idea has legs but I'd worry about its defence physically, economically, culturally etc.