Its kinda hard to do, blockchain needs a connection to verify any transaction over the network. If no connection, then no one can verify it, means its cannot be processed.
That is very clear, because basically it has been seen that every Blockchain always needs a strong network to get something they need done, so there is no story to build a crypto project without the internet.
Not about the internet but can we build a network base on other forms of communication? Say, someone, launch a satellite that take this exclusive signal to keep and maintain an exclusive blockchain. I don't know how dumb or possible my question looks since I'm very noob about this but I think if a crypto project is able to do this, they don't have to worry one day, the internet around the world go down.