There is an old analysis of the "E" clades in Italy based on Boattini and some prior papers.
The averages for E-V13:
No. of Samples: 69
% Italy as a whole: 7.81
9.3 (Northwestern Italy: Cuneo, Piemonte, Savona and Genova, Liguria, Como and Brescia, Lombardia)
11.0 (Northeastern Italy: Vicenza, Treviso, Aviano)
6.9 (Emilia Romagna: Bologna)
4.9 (Toscana: Massa/La Spezia, Pistoia, Grosseto/Siena)
6.5 (Central Italy: Marche, Umbria and Lazio, i.e. Macerata, Foligno, Terni)
10.6 (Southern Italy including Messina in Sicilia)
7.1 (Sicily: Agrigento, Catania, Siracusa_
2.4 Sardegna
The entire discussion and breakdown can be found here. The analysis is dated, but the data is clear.
Distribution of E1b1b subclades in Italy (Boattini et al.) (eupedia.com)
In fact, I think I'll just add the data for ease of reference:
North Italy
In Cuneo, south-west Piedmont,one E-V13 (3.5%).
In Savona/Genova, central Liguria, seven E-V13 (14%).
In Como, north-west Lombardy,four E-V13 (9.5%) and one E-M78 (2.5%).
In Brescia, north-east Lombardy, two E-V13 (5%).
In Vicenza, central-west Veneto, five E-V13 (12.5%).
In Treviso, central-east Venetotwo E-V13 (6.5%).
In Bologna, central Emilia-Romagna, two E-V13 (7%).
Central Italy
In La Spezia-Massa, north-west Tuscany, no E1b1b (0%) was found out of 24 samples.
In Pistoia, central-north Tuscany, only one E-V13 (7.5%) sample was found out of 13 samples.
In Grosetto-Siena, southern Tuscany, five E-V13 (6%).
In Foligno, central-east Umbria two E-V13 (5.5%).
In Macerata, central-east Marche, three E-V13 (7.5%).
South Italy
In L'Aquila, Abruzzo, E-V13 (13%).
In Campobasso, Molise, two E-V13 (7%).
In Benevento, Campania,three E-V13 (8.5%).
In Matera, Basilicata,two E-V13 (8%).
In Lecce, Apulia, 6 E-V13 (15.5%).
In Cosenza/Catanzaro/Crotone, Calabria, four E-V13 (10.5%).
In Catania, three E-V13 (5%).
In Ragusa, southeast Sicily, three E-V13 (6%).
In Agrigento, southwest Sicily, four E-V13 (9.5%).
In Olbia/Tempio/Nuoro, north-east Sardinia, only one E-V13 (2.5%) sample was found out of 40 samples.
To me, in almost all cases it looks like movements from coastal areas, where Greek settlement and trading centers might have been the cause.
I know that there has also always been the feeling that some came directly from places like Albania and Croatia, and it's possible, although I don't know why the sample from the Marche would be relatively low in that case. Perhaps it's because of low sample sizes.
Both sources are possible.
There's also the old Cruciani et al data, which everyone still uses. It's particularly interesting because it has data from all over Europe. Czechia and Slovakia, Hungary, Moldovia and Ukraine have interestingly high numbers.
https://academic.oup.com/mbe/article/24/6/1300/984002