Having travelled around Europe over the last few weeks I'd make the following generalisations. Of course, you need to take into account the inter-breeding over generations which means no country in Europe is homogenous, but I have noticed some things. Anyway, this is what I've observed based purely on seeing guys with soft dicks in changing rooms and other non-sexual locations.
Sweden pretty average, but with thick foreskins.
Norway same
Estonia average, maybe on the small side, but full looking dicks, so possibly showers.
Latvia no idea, they're quite hung up about public nudity.
Czech average on the small side. The largest I saw in a public change-room actually belonged to a teenager.
Germany small, with long foreskins.
Italy petite.
Of course, this is only soft I'm talking about, and always seen in a public change-room setting. But interesting, don't you think? Or just bullshit based on inaccurate observation?
Looking forward to seeing what Holland has on offer, based on the other threads I've read recently.