Front Windshield Wipers Stopping 1/4 of the Way Up - resuming after a few minutes of warming up

First of all, not sure if this is a cold weather issue, I think it happened once or twice before the snow (ice) at around 10+C weather.

Ready mode, wipers start going up, they stop at 20 degrees or so. Regardless of the switch's position, they won't move. I let the engine to warm up and after a 2-3 min they resume wiping.

Last night it was -10C. I had to do a bit of driving before they resumed wiping. Almost as if the warmth from the engine affects something, but I could be wrong.

I read that my wipers' motor might be on its way out. How can I test if the motor is faulty without buying another one? What else can I test (and how)?