So, I dropped linux on a laptop, and other than a few expectable hangups everything works fine, except for one big snag: The font on the login screen is gigantic and everything is overlapping! It isn't a resolution problem, I can tell it's the same as it is on the desktop, it's just the font size is utterly out of control.

I'll feel really dumb if you can fix this through the kde control panel, but does anyone know how to solve this?

there are a few things it could be, but most likely your DPI settings are not being detected properly.... (when you are logged in, you probably have forced KDE to use a certain dpi for fonts (eg 96))

I have done the following on my Dell Latitude C840 that does not detect these things nicely... (cut and paste from my internal wiki... so formatting might be funny)
You will need to change the displaysize values - they are my laptop measurements using a ruler... so measure your own (unless these work - 15" dell screen)

There are a few other tricks... but hopefully this will fix it