Winter #ue4jam: February 8-11th - THEME: ON THIN ICE

I was thinking of trying to aim for the tiny category, as I love procedural content.
To prepare a bit I’ve tested packaging minimal builds, and I’ve got some questions:

Is the 100MB limit for the .zip archive, or for the extracted files?

What files must be included? Say I was building for windows, could I exclude the UE4 pre-req distributable? (which is 38MB)