After only a couple of days the temperature is steady between 65 and 75 degrees. The humidity is stuck around 67% but maybe that will bump up too in a day or so. So all in all it looks to be working pretty well in the Igloo cooler. I've got a digital hydrometer inside and I'm checking it daily.

Thanks again guys for all the advice.

67% is just fine.65%-70% is my personal target.Well Done :0)