A lot more things other than bitcoin would be the point of concern if the internet shut down for a while, bitcoin would be least of concerns.
However if it does, then we have wait till it gets restored and then the network would start working again. It will just pause a while, it cannot be stopped..
Maybe in future we might find ways to solve this problem and use bitcoin even if the network is down. I see some people talking about Lora, I have heard about it but not how it is used.
The only thing I know that could make the Internet to shutdown worldwide is world war 3 and we should be getting ready for that.
Like how ? I do not think anything will be left if world war 3 happens.
My country never fought in WW1 and WW2, it is none of our business, the highest war that took place here was civil war, and so is the same with many other Africa countries, if war is brewing it is better to exit your country as there will be many signs available. Bitcoin transaction will freeze on the blockchain until the internet is back and even if it takes over 10years Bitcoin will be well preserved, people need to stop worrying about what could happen to Bitcoin if the internet goes down.
As for those talking about WW3, it will be more bloodier than the past because of the tools of destruction that's available today, generations of generations will seize to exists and it will take decades to heal from it, think about something like Hiroshima and times it 10x, atomic bombs today are marginally more effective than what hit Japan in the past, don't pray for war but peace instead.