Having 2 or 3 different servers for a website with low traffic like this, is a suicide.
As a marketing agent having worked with huge online games such as oGame and Tribal Wars, I'd like to propose something way better.
Why not implementing Different Schools in the same WoP server? Keep Hogwarts being the UK/English school, then add another one (Say Durmstrang, say anything else) for German speakers, but maintaining the same organisation as Hogwarts, and then do the same for the south of Europe (Beauxbatons?), having a school where Spanish and French post could be allowed.
Then, implement ways for the students to be able to visit and interact fluently with other schools, keeping it all together, uniting the flow of visitors in the same page, but diverting the language choices.
Customer support service by UserEcho