All I really want is assurance that the TV show will be finished, and the number of people in the internet that's given up on that chance is too high for me to ignore.
HBO has already announced that the TV show will finish properly and that the story will be concluded as originally intended. The producers have been told the full story and they know how to proceed. It will overtake the books from 2016 onwards. (Unless Winds of Winter comes out this year or the next, in which case the series will overtake the show in 2017). The series will end in 2018 or 19.
I hope you realize that HBO doesn't go out and buy the books from a bookstore and then adapt it. The actual author is an Executive producer of the show and he has made sure they know exactly what happens to all the characters, in case something ever happens to him.