I am Zwifting on a 2016 Macbook (the 12" retina one with the Skylake m7 CPU) and have problems with overheating. After 30-60 min. of riding (with external 1080p monitor via HDMI) it hits close to 70 Celsius CPU temperature and starts throttling, which results in Zwift app hicups.
I guess I have to invest into active cooling for the laptop. Any other ideas?