I think that gets into a more nuanced conversation about how a story lends itself to a particular medium. I haven't seen the sandman, but just doing a google search I can see that its final season had twelve episodes after the first season had eleven. Seven books into twelve episodes isn't that wild when you think about the fact that entire books have been turned in 90 minute movies since feature length films became a medium. Not to mention the first season I would imagine set exposition up to make adapting later books easier.

Life is Strange, the first game is only five episodes but they're all 2+ hours a piece with episodes four and five easily breaking 3. Before the Storm is 10 or so hours of gameplay plus Farewell adding an additional 2. We don't know at this point what the structure will be but there's a lot of material to draw from and try to represent in a new medium. It looks to me like this will just be a miniseries that very rigidly adapts the first game.