Thank you very much for all of your suggestions, they look very interesting and if not with them, we might go on our own as well!
Since they insist on going to the beach, I am thinking to spend 3 nights in Cariló but I am having a hard time with accommodation. I have been there a day with a car and saw many beautiful houses and some apartment complexes and hotels, however online I can't find price and availability for these.
I understand that the beautiful houses are rented by the week/half a month/month, but what about the apartments and the hotels? The various websites I found always ask to call for a quote!
We would be going there by bus, so I don't think sleeping in the neighbouring towns would be okay, albeit cheaper.
http://www.carilodirecto.com.ar/
http://www.carilocottage.com.ar/