I'm Italian, it depends on the school...some go home at lunchtimes and go in on Saturday mornings, others finish at 3ish and don't do Saturdays, when I was a kid it was common to have Wednesday completely off.
Not a lot of Italian women work full time, and people are more likely to live in their 'home towns' so have family and friends available for childcare. I think people will be wary of using nonnas for childcare but there'll usually be a sister/cousin/neighbour to do childcare swaps with. Getting an older teenager to do a few hours tutoring is really common as well.
Also Italy is made up of more large villages and small towns than the UK (and less million person plus cities) so I think class and school sizes tend to be smaller. Village primaries with a joint class of say 6 kids in year 3 and 8 in year 4 are still pretty common.
I think it's a good plan for Italy but wouldn't necessarily work in the UK due to our different demographics and weather.