The war aint over yet, Spain still have over 100K troops while France don't have half of that. Besides, i don't have to ship them over, i can simply walk through Austria, in fact spanish troops is marching as we speak to assist the Austrian defence.
The Habsburg will continue it's struggle to fight of the muslim hordes from invading the christian world, and we will do everything in our power to prevent France from invading the HRE, giving them Alsace would give them a open door into Germany. The French forces will be destroyed, and the Spanish king is convinced that we will manage to do that.
Southern France have already fallen, it's just a matter of time until whole France has too.