Adding and reading a static HTML page with The requirement is that the user can upload a folder, containing static HTML, CSS, JavaScript files, and a link is generated.

So, then I don't want to have any drupal styling whatsoever.

My initial idea


Set a specific content type, allow multiple file upload
Upload all the files to a specific directory via some kind of rules 
Access the page at www.example.com/sites/default/files/MYFOLDER/index.html


Do you think this is feasible approach?
File (Field) Paths allows you to specify path using node fields. Using it, you can have node's files in directories like sites/default/files/custom_pages/[nid]/[node_title]/
Just make sure to put .htaccess inside custom_pages folder, one that will allow direct html serving.

Then you can generate link using the very same tokens.