i think it is possible
as far as i am aware from memory (i used to work in Greece) you can complete both your cpl and IR in some other jaa countries if you have a uk theory atpl. the issuing authority (for example HCAA= greek caa) has to approve/recognise the atpl theory, and from what i can remember HCAA do recognise the UK ATPLs. the spanish caa do not.
that part should (and i used the word should carefully!) be pretty simple, unfortunately the time frame to have the licence issued is not straight forward! take care with your decision!
search other threads for time frames for licence issue of other jaa countries, and what others have come across when training in other jaa states! the IR can be done anywhere in jaa land.