The symptoms are of a compressor clutch that's going intermittent, it's not a blend door issue. Blend door issues manifest as a "loss of control" of temperature, especially noticeable by WILD swings in outlet air temperature particularly when accelerating or decelerating. Simple "loss of refrigeration" is usually caused by the compressor clutch not engaging when it is supposed to.

Check your compressor clutch gap first. Excessive gap will cause the compressor to engage intermittently (if at all) and becomes more noticeable after the components heat up from operation.

Recommended gap is .014 -.030". Usually, an excessive gap can be resolved for a while by simply removing one of the shims behind the clutch hub aka a "shimectomy".

Next time it fails to cool, pull over, pop the hood and visually check the clutch hub to see if it's engaged or not. If not, tap the face of the hub (stick, dowel rod, screwdriver handle, whatever) and see if that causes the clutch to snap in. If it does, diagnosis of excessive clutch gap is confirmed.

This is an example of a much more severe condition due to bearing failure in the pulley. It often results from having the clutch hub disintegrate and "wobble" as it tries to continue operating. Failure to address a bad hub and pulley bearing can lead to a collapsed bearing, a locked up engine, and a ride home on the AAA flatbed (don't ask how i learned that!). Remove belt and manually check pulley to diagnose if it appears locked up.