- Offload all static resources to a CDN (the usual leech from google/maxcdn/etc)
- Leech imgur for all images (you can quickly make scripts that post all images you upload to WP to imgur instead, and check every now and then for them being still live and re-upload when/if they go down)
- Install, optimize an nginx + mariadb + php-fpm stack manually via ssh (so your VPS is as minimal as it gets, no phpMyAdmin, CPanel, etc)
- Use a Redis cache, so the page is rendered only on the first visit to it, then loaded from Redis on every consecutive visit (not a WP plugin or any of that shit tho, use the NGINX HTTP Redis caching module)
I say "average" optimized because this is doable within a 15-30min installation after following a few decent tutorials here and there (and is basically the checklist every page speed tool out there presents).
If you want to go the extra mile, putting yourself behind CloudFlare, leveraging their caching layer and RocketLoader (I think that was the name for their JS optimizer), you can actually match Node's performance