Speedy, I would check the base level of N864 around BCN, if you go that way as my chart shows F55, with lowest use at FL60. Also, remember that if you are IFR, you may end up IMC, and your Min .Safe FL, for your track may require you to be at FL60, or higher depending on the QNH.
Remember, there are Danger areas off the NW coast of Devon/CW, up to FL100, if you track direct SW.-SI.