It all depends, I think that Fiat is most likely to be important at a time like that. And why I think so is because despite what you will be needing is shelter and food, you would still need money to purchase food and to pay for shelter, although that really depends in some situation. But, mostly you’d be needing cash and that is what most people would think.
In conditions of conflict, it is very important to choose fiat for basic needs when the government does not distribute food on time. Unless there is a service or merchant accepting bitcoin payments it may be an alternative to using bitcoin but in conflict conditions it is not possible to have a crypto acceptance service even though P2P.
But that doesn’t make Bitcoin any less important, they are all good, and I don’t really think it is that much necessary for anyone to be selling their Bitcoin unless maybe you do not have much money in your bank account and you feel that you need to sell some of the bitcoins that you have to kind of cover up for what you are lacking at the moment.
If no conflict means no decision to change fiat currency from bitcoin, all expect long term investment but conditions do not allow, then the option is to change btc to fiat currency to meet basic needs Basically, if bitcoin is part of an asset then I am very sure they don't 100% convert it to fiat.