A Project has many Sites. Both Projects and Sites can be viewed and edited. What’s a good experience for this that doesn’t overwhelm the user?

Web app where each Project contains many Sites. Projects and Sites are able to be viewed and edited. I have a feeling that clumping everything on one screen might be a bit overwhelming, especially considering that each Site's "lots of info" is scrolling a couple full browser heights.

So currently I have a table of Project rows like this with nested expandable rows to preview the Sites.

Project1
  - Site1
  - Site2
  - Site3
Project2
  - Site1
  - Site2
  - Site3

Then when you click on one of the projects, it shows that Project's description and info for all of the Sites.

Project1
 - info
Site1
 - lots of info
Site2
 - lots of info
Site3
 - lots of info

I haven't deciding the editing part yet, but my first impression was that editing here might be too much information all at once.

A Site always belongs to a Project. Should they be viewed separately or together? Should they be edited separately or together?

I tend to like using the same screen and modals, but this feels a bit different because it's so much information.