I don't recall any civil wars or widespread beatings/executions when people found out their neighbors immediately sold their Zimbabwean dollars for USD. I don't see why widespread BTC preference over failing national currencies would be any different.
We're talking about America here. This isn't Zimbabwe.
Now, back to the OP,
I can see some of those things happening. The civil war would probably be unlikely, or at least not on a really large scale.
If we have to, we could all flock to a 3rd-world country and live among the locals, explaining Bitcoin to them and the like. (Or, we can finally fund the freaking Bitcoin island idea.)
I won't be surprised if Bitcoin gets blamed for the collapse, or at least is claimed to have had a major role in the collapse. People are stupid. They listen to whatever Fox or whoever tells them, as long as it's a fancy source. Regardless, it would be hilarious watching the news fumble over themselves trying to explain why it hurt the economy.
Do I have plans? I guess. Hide away in a forest close to where I live for a few weeks, watching what the rest of the community is doing. If everyone seems to be going to a single spot, or at least a condensed number of spots, make a beeline to the airport and join them. Or I'd leave as things start going bad.
Yours is a dark scenario, but I wouldn't call it the worst-case scenario. A all-out nuclear war on BTC owners would be the worst-case scenario.