HN traffic is not nearly the DDOS people make it out to be. I made it to spot #2 once and that was a few dozen hits per second at most. Maybe not something to serve with wordpress from a raspberry pi, but hardly apocalyptic levels of traffic.
Wordpress on a raspberry pi will handle static, properly cached content just fine.
HN itself is run on a single server. So long as you’re not running something bloated or trying to host on a DSL connection, you’ll be fine.
previous HN articles linking to instances has caused them to become overloaded. this instance just seems to know how to handle it