That's the tough and hard thing about using a currency that is based and used for the internet and the only chance for it to survive would be the internet being online and running, though to do this day I don't think we could ever go through something like that and no government in the world would never allow such a catastrophe to happen in the least, the internet is going to live on forever at this point.
So, this is never going to happen bud and Bitcoin will live on forever.
Everything is possible, so you should not rely solely on bitcoin. In the case of collapse, you need to have other values for survival.
yes you are right that we should not rely only on bitcoin because in case of any incident internet connection could totally damage, but i think the condition of internet will not remain damage for longer period of time because majority of people in world use internet for their work, of-course the great engineers will do their best to repair the internet connection.