A first quick comment.... I think you are spending too much time in Carmelo, there isn't a lot to do there. I would rather spend 1 more night in Cafayate where that additional night will give you a far better return that the same additional night in Carmelo.
There is an expert guide over on Trip Advisor (Angie/Giena) is I believe her name and handle... she is the Northern Argentina expert, you need to get in touch with her. Im trying to dig up an email contact for you, will revert back once I can locate this information.