I believe I've said before that before you can define the term 'survive', you have to define the term 'humanity'. They can both have vastly different meanings, as MPRyan points out, which are constantly changing.
Oddly enough, humanity stands the most chance with the third, and I believe, most likely option, i.e. Heat Death, because whilst the other two options are irresistable events, Heat Death is just a general smoothing over of energy. You need a race that is really good at manipulating its environment to shake things up, and that's where races like 'Humanity' come into play.