Yes Fabrizio, I agree, I had also intended to mention that July, and particularly August are the peak holiday periods and that the cost of hotels etc. is much higher.
The period you suggest, from mid May to June, can have fantastic weather here on the lake. This year has been a bit strange but we also had a period of good weather in September and it was still warm enough to swim in the lake.
I am very curious as to whether you find the sun visors useful and also, having lived with the beautiful wood rimmed steering wheel, I was wondering how comfortable you find it on a long distance drive.