Gold! Bitcoin is safe when the world is safe. World is heading towards WW3. We can experience power outages. No power - no bitcoin acces.
Producing electricity is not very difficult, even during major warfare. Portable solar mobile chargers are available from Amazon for as little as $5 per piece. But these devices need frequent maintenance, and it will be better if you could store the manuals and tutorials carefully. Survival will be tough during the WW3. You need to push it really hard, in order to survive.
Glad to see someone really knows that its not that easy to cut down power to all world, and shut down internet. All talk about WWIII, I think it wont be anything similar to previous ones. Europe, North America and especially Australia should be rather safe to live in next decades, wars will be fought as now, Middle East and Africa.