Night train from Granada To Barcelona?

I have no knowledge to share re: the night train.

If you are open to the flying, the flights are quick, easy and very inexpensive if booked in advance. Our experience with Vueling from Barcelona to Granada was painless.....it's far from a luxury airline, but it got us where we needed to go and quickly.

The last I heard was that the night train was suspended due to the track construction around Granada. The schedule for that work is open ended.

I also recommend just flying.

Do not bank on the night train ever restarting.

As Douglas has mentioned, the 'Trenhotel', Granada-Barcelona has been temporarily suspended since August 2nd, 2015, due to the railroad work on this route (you may read this notice on the Renfe site, under 'Avisos', but it's only in Spanish)
Be aware that there are only 2 trains traveling this route daily & they are Bus + AVE combination, which means that you will travel via bus from Granada to Antequera, then transfer to an AVE train which will take you the rest of the way to Barcelona.

I'd probably fly to Barcelona as others have recommended.

I also agree with flying in this situation - check Skyscanner for options: http://www.skyscanner.com/

"Do not bank on the night train ever restarting."

I agree and here's why. The reason the night train is no longer running, and other routes out of Granada require a bus connection to Antequera train station, is that they are extending AVE (high speed train) service to Granada. On other routes with AVE service, the night trains have been discontinued - so it's reasonable to assume the same will be true of this route.