Switching domains is easy, hive.blog and ecency.com are open-source.
Ecency even has an application, which can be downloaded on any desktop, and does not require app store approval if push comes to shove.
Any files can be downloaded on PCs, it just takes a bit of technical know how. If hive gets attacked, the info will spread quickly and people who believe it's worth it will be able to get access to the blockchain.
The biggest issue is obviously nodes, as people running them are not anonymous and might decide to stop running them under pressure. As hive gets bigger hopefully the number of full nodes will increase. But even then, it is a fundamental tradeoff of DPOS to have a small amount of nodes.
The reason I remain bullish is because I know there will always be countries defending freedom of speech, and there is no reason nodes can't be hosted there, legally.