They serve around 600MB per month (calculated based on the 2015 traffic numbers and current page size of 4.19KB).

Based on their IP, they are hosted on DigitalOcean where even the cheapest plan provides 1TB of transfer per month, so bandwidth is not an issue.

I think they host it on their own home server, or at least did at the time of the WIPO case, since that mentions conserving DSL bandwidth.

OVH has a 1MB plan with every domain which has unlimited bandwidth.