I know that this category isn't necessarily meant for schematic packs, but it's the closest thing to it I could find.
Click here to download the schematic pack. It's a zip file, all you have to do is extract it.
To use this, you'll need MCEdit. Click here to get it.
Okay, so it's not complete, but I will be adding to it in the future. This is NOT simply a copied-and-pasted Ender stronghold. This is made in a larger scale, so it will take slightly longer to make, but it will look a lot cooler. The set currently contains the following:
-hallway segments (straight, corner, t-junction, intersection)
-portal room (wouldn't be an Ender stronghold without it)
-"enderporter" (or "endervator", considering that it serves the same function as an elevator)
-cells (like I said, a dungeon)
-library room (with fountain)
Like I said, it's not complete. However, I'm going to add more later.