As a French resident, I would question the dates given in the Easyjet website. The next 'general' strike is called for SATURDAY 6 NOVEMBER, which was announced with that of 28 October at least a week ago, as required by French law.
IMHO, I think it's a case of Easyjet warning the general public of disruption to minimise problems for themselves in encouraging the public to transfer their flights to other days.
And it all depends on where you are flying to or from in Spain. There are air corridors that avoid French airspace (though which are likely to be fuller than normal, hence a short delay).
Incidentally, the ATC personnel are normally asked to 'disrupt 30-50%' of air traffic not stop it completely. Just unfortunate if your flight is in this particular category.
AA - I'd like to know where you found the information that 4 November would be the peak day. It doesn't ring true with any local knowledge. That said, I hope you and Mrs AA get away on time and have a great holiday.