They'll also play another Copa final two weeks before against their arch rivals. We can only hope they won't be at their best when we play them but won't be an easy game anyway. They live for Copa and Marcelino also knows how to play against us in knockout games (not so much in the league though).
Fighting back against Sevilla to go through will give us enough momentum and confidence I think to get the trophy. Strange situation for Bilbao with two cup finals so close together.
In a month or so we'll know if we're in with an opening for La Liga. If that is out of reach as it will probably be, I expect us to prepare the Cup final very well, and to put on a great performance vs Bilbao. Resulting in a comfortable win.