Here's the thing. We can deduce that some of the basic ideas survived. In January of 2013 there's a big meeting at Lucasfilm, with George present.(this is only meeting of new films where George is present) Alot of art is shown, including ideas for the first Jedi temple, one of which is approved by George. By February 2013, the concept art for Luke has taken a shift. Now he's seen in various states of depression. In two he's just sitting letting sand pour on top of him, slowly burying him, and he doesn't even care. In one he's imagining the two suns of Tatooine. In another he's being haunted by a Dark Side specter. Also in February Doug Chiang paints Luke's x-wing submerged in the waters of a sea.
And for comparisons sake, Rian submits his first draft for TLJ March 4th 2015.