Well, if there's a total internet blackout, I think you'll have bigger things to worry about than not being able to access your Bitcoin.

Basically, every form of internet communication will be disabled, including email, web, online banking, social media, and even communication apps like WhatsApp and many other services. In such a scenario, people would likely turn to alternative means of communication and transactions, such as using cash (in many countries, card payments on POS systems and ATMs may also be affected). Plus, a widespread internet blackout can have far-reaching consequences beyond personal finances and communication. It can potentially disrupt essential services such as emergency response systems, transportation, and logistics, making it difficult for people to access medical care, food, and other essentials. We rely so much on the internet for everything these days, so it's a pretty scary scenario to think about in the modern world.