Having an internet shutdown is a threat to bitcoin, simply because bitcoin itself is operated by the internet. So if there’s no available internet connection, bitcoin transactions will never be possible, but bitcoin will never be lost, they’re always intact in our wallet as long as they remain untouched.

But I don’t think this will be allowed by majority to lost a connection for one week. Even just for a day, big companies will already complain for that, so I don’t see it possible to happen except if there are unexpected war or fire incidents that would shut down all internet connections.