I drank a few beers and a shot Wednesday night and continues having about 4-5 drinks of vodka and whiskey. My last drink was at 12pm Thursday. I have an EtG test on Sunday by 2 pm. I've probably drink a gallon of water and half a gallon of cranberry juice. How likely is it that I will pass?

Drinking water and juice helps ZERO, you may fail for dilution. 50/50. If it is a real problem, you have a choice to make, drink or don't drink, simple as that.

I would be amazed if you passed. What's the cutoff level?

The test claims an 80 hour window of detection so its close. Drinking water and juice are of no help but could cause you to fail.