Ford Fiesta AC restricted flow after 2-3 hours

What is your question?

I have a 2011 Ford Fiesta SES. For probably the 3rd or 4th summer in a row I have been experiencing issues with my AC. It blows cold and works totally fine until I drive for >2 hours straight. After that, the air flow seems to get restricted and even if I crank it to max speed, only super minimal cold air flow comes out. You can hear the blower get louder as you increase the speed but the amount of air being moved does not change and is super minimal. This is really only an issue in the summer time when I have the AC on the entire time I am driving. The cabin air filter has been replaced.

What makes this problem better or worse?

Driving for 2-3 hours.

How long has your 2011 Ford Fiesta had this problem?

Multiple years.