Our ability to create, record and maintain data is increasing exponentially. Someone in Indonesia was able to get a message 35,000 years into the future using a cave and come paint. We have only gotten better at preserving data since then. I think it's safe to assume that at least some of the information we record will survive as long as there is someone around to care.

I don't think that two works of fiction from the last century are reliable indicators of the longevity of our species. I look more to the historical evidence we have of the resilience of humans. I don't know if we will be around for millions of years but I don't think we have reached midlife.