We stayed 8 nights at Dario's place with 2 small kids. We were amazed on the size of the apartment (it is very spacious), balcony and the view (the lake and mountains! we spent most of the evenings on the balcony by just enjoying the view:-)) from there as soon as we arrived. It was just perfect in every way.
Dario and his mother are very very friendly and helpful (they arranged baby chair for our youngest one and helped with garbage).
The ferry port to Monte Isola island is just across the street.
I do recommend to visit the island for everyone (very cozy restaurant with an amazing garden - https://goo.gl/maps/A7iiX95ektM2).
Lovere is in a decent walking distance, we were afraid first about it being too far away but in reality it's very ok. (best ice cream place we found - https://goo.gl/maps/QRfordK5N642, they bake also fresh bread and cakes).
The Lake Iseo does not have so-called standard beaches where one can walk into the water but we found one near Castro - https://goo.gl/maps/ocWiay7uk2E2 (with restaurant and picnic area).
Highly recommended to everyone!