Yes it's possible but keep in mind that the UI was not designed to be scaled like this and most of the alignment will break.
When loading the Client creates 5 fonts with different sizes. These fronts have indices that are analog to the FontIndex property in the Interface Text files (resinfo)
Code:
FontIndex=INTEGER,"0"
All the non-ui rendering stuff like character names probably have their font index hardcoded so if you want to exclude that you'll have to find it or move all UI fonts over to another index.
Now onto the editing...
CGame::CreateFont which is at 00BA6140 takes parameters like the font index, size and name. The font name comes from UIC_STT_FONTNAME in textuisystem.txt and is by default "Arial".
So in order to edit the sizes of various fonts you'll have to find references to the CGame::CreateFont function.
You'll end up at one of these locations and can change the font size according to the labels I provided. Don't modify the font index in the assembly!