I think neither will die, because they are decentralized systems, with many nodes, and because internet is everywhere now.
Exactly, but considering this scenario hypothetically I don't think Altcoins are going to completely be dead should Bitcoin happen to die unless there is no internet in the world else whatsoever that killed Bitcoin will be corrected by new and emerging Altcoins.
Ya some what right. No one can replace the bitcoin. Bitcoin is the king of all altcoin. So if all the Altcoin die means,the bitcoin will be long lasting. If you have a idea to inverse in altcoin means,just inverse in bitcoin instead of other Altcoin. Why because, the king only give you very huge return.