A/C and gas Mileage

Has the Idaho National Laboratory done equivalent test for non-hybrid cars so that we can compare apples to apples?

You are referring to this article:
https://www.hybridcars.com/air-conditioning-effects.html

No, the labs have not done similar tests for non-hybrids.

It's inevitable that as gas mileage increases, the percent of power that is needed for air conditioning will increase as well. After all, if zero energy were needed to propel the car, 100% would go to the air conditioner. This would mean infinite mpg with the A/C off and some very high mpg with the A/C on but the mpg dedicated ot the A/C would be Infinity - some very high mpg but that is still infinity.

Compare this with a fuel hog vehicle. You practically can't see the impact of the A/C becaused it is masked by the propulsion system.

For the systems engineers out there, this is because A/C consumption is a function of time (gal/hr) while propulsion consumption is a function of distance (mile/gal) These are added together to get the composite mpg that the consumer sees.