I am not too bothered about the precise number of nights here and there as long as you do not mind travelling by day. I take it you are planning to see the Alhambra in Granada which is one of Europe's greatest sights - although I confess to disliking the town for more than one night. You should prebook your ticket.
If you care to e-mail me on davidcross@frogsmore72.fsnet.co.uk I will send you some folders of notes on Andalucia which you may find useful.