Well...
Patch 8 was 40GB ... and it was single new class ...
Patch 7 was 32GB ... and it was single new class ...
Patch 6 was 60GB ... and it was single new class and new region ...
And for Patch 5 Larian as it seems didnt anounced the size, so i dont really know.

Anyway, if this tells us anything, it tells us that patch size dont tell us much about its content.

Most of it can be visual (models and textures), or sound files ...
Lots of it will be replacement of curently existing things ...
After all ... we download 33/85 of that game again ... so logicaly, almost half of it will be changed somehow.
And since our curent game size is 104GB ... we may aswell loose some things.
//Edit:
That, or Larian once again found some way to save some space on our machines, and this patch is just really complressed beast, that would in older patches take twice as much space.

Who can really tell?
