It depends on how widespread the crackdown is. It would take a very well coordinated global crackdown.

Governments can't afford to keep internet shutdown for long, its causes a lot of economic strain.

Most money is digital fiat and it doesn't work without internet.

You can connect to the blockchain via satellite, but that means relying on blockstream an American company, and the satellites are third party, Samsung etc.

I have no idea if it ever came to anything but some researchers were updating blocks over long range radio signals awhile ago.

The network is far more resilient than anyone realises.