Hello,
This sounds very interesting; something I really enjoy doing.
I am thinking two separate approaches here:
1. The Direct Approach
Optimize WordPress performance (in some ways that do not involve the use of caching plugins) and
2. The Indirect Approach
Tune and optimize the host/server performance - largely possible only if you can provide root/SSH login to the host.
While I can not guarantee 4 to 5x performance boost, I will certaily speed it up to at least a noticeable extent. With root access, I can probably get closer to your goal.
If you want me to give this a try (my best shot, btw), kindly initiate a freelancer chat/message session with me.
With best regards,
Richa V