I've been thinking about this Anna, and to be honest, I don't have a clue. We went to an agriturismo in Tuscany this August, which was in the middle of nowhere. We tried to go to the seaside once (a good half an hour drive) and we were shocked by the amount of people at the beach.
Puglia is gorgeous, but again, not in August.
I'm told that San Vito lo Capo in Sicily is beautiful (it's near la Riserva dello Zingaro, marvelous sea), but again, not sure what it's like in August.
The western coast of Sardinia (quite windy though) might be less busy than the rest of the island...
what did you have in mind, btw?
Hothell, I think it depends on the age. I would be firmer with a four yr old than with a 2 yr old. I'd tend to behave like you are describing, but when it's between ds and dd I try to keep quiet and at times they come to an agreement (mainly because dd is very laid back. so I often feel I should "protect" her and I intervene). With friends, ds's always been quite generous, so I haven't developed a strategy to deal with this.