Plugged evap sounds very plausible, but here's another thought, courtesy of an old VW Beetle driver.
In the Beetle's handbook it recommends slightly opening a window in winter for maximum heating and defrosting. Sounds counter-intuitive, but that car was so tight that heated air could not get into the cabin unless it had a way to get out. I've seen Beetle drivers in winter with fogged up windows (sometimes dripping like it was raining inside) who never read the handbook.
The Forte is likewise a tight car. Under the back glass on the package shelf are two vents to let out the incoming air. See if those are blocked.
In the Beetle's handbook it recommends slightly opening a window in winter for maximum heating and defrosting. Sounds counter-intuitive, but that car was so tight that heated air could not get into the cabin unless it had a way to get out. I've seen Beetle drivers in winter with fogged up windows (sometimes dripping like it was raining inside) who never read the handbook.
The Forte is likewise a tight car. Under the back glass on the package shelf are two vents to let out the incoming air. See if those are blocked.