I’ve been putting blogs and sites up for national NGOs with Wagtail, a Python/Django-based open source CMS, run my personal blog on Ghost, and the School of Data in Switzerland runs for free on Jekyll and GitHub Pages. The Swiss chapter runs a Wordpress farm. If nothing else, this lets us test the limits of open content, porting articles to and from platforms like, ahem, Discourse. Thank Jimmy we still have Wikipedia to sort through this mess of IT! 
On a more serious note, these kinds of attacks suck, and I encourage everyone in the vicinity to use a quality provider of secure CDN caching and DDoS protection these days, even for smallish sites. What are the channels where issues and questions like this one will be discussed in the months to come?.. Tools - Open Knowledge Forums ?