Why I’m Moving Away From WordPress

My guess is that you should get rid of your own server and host your blog somewhere else where they are capable of hosting Wordpress and deal with traffic spikes.

If you do want to keep your own server there is plenty you can do:

1) Use some Wordpress level caching.

2) Install something like Varnish (https://www.varnish-cache.org)

3) and/or load balance your server with NginX (http://markmaunder.com/2009/12/01/how-to-handle-1000s-of-con...).