For those of you who are interested in watching tonight's game I think I've found a pretty reliable source.
According to this site you are able to watch all the Carranza at this link. Which makes sense because it's Cadiz's local station. As Maddi said the game kicks off at 10pm. A win would be great for confidence and would set us up with a match against Cadiz in the final, they beat Bilbao 2-0.
Edit - Thanks alex for this alternative link and as Kenneth said La Sexta will now be broadcasting the game so that should make more streams available, indeed Rojadirecta is hopeful that it should have a few streams before the game starts.