I don't think we need to be worrying too much about what's going to happen after 7.5 billion years or even quarter billion years from now.
I forgot when the Homo sapien arrived but Human history is merely 12 K old and w/ in this time frame we adanced to an extradonary level. All creation have its ends. Human race WILL be instince on earth one day no matter what and this planet will prabobably become inhabitable for living things. If we are lucky, I think we will find similar planets where we can move to.