Zelda has a lovely place really close to Sacre Coeur, and she was really helpful and accomodating in times of checking in and out. The flat is exactly what you need for a few days' stay in Paris, and if you feel like having a in-flat breakfast with a view over Paris' rooftops you'll enjoy it even more (fixing your breakfast is a breeze, a wonderful boulangerie is just around the corner!). I can't do anything else than recommend! :)