Hi Greg,
I have found that the camera generates enough of its own heat when running in the cooler box to be the warmest point in the box, and because moisture goes from hot to cold it has never had any moisture on the chip form when using it. All the moisture ends up on the old side heat exchanger.
I have a styrofoam lid that press fits into the box cavity and I find there is only a few drops of water in the box at the end of an imaging session, and the angle the camera is at when on an EQ mount means it is almost always at the back or Sid of the box and nothing a small piece of cloth or paper towel can soak up
The only other precaution I take is to let the camera run for a while after I turn off the cooler as again it let's the cameras internal temperature rise above that of the dew point at night so when I take the field flattened off and the camera out of the box there is no moisture ingress into the camera.
I hope that explains it? Let me know if you want a picture of it with the camera in the box?
Cheers
Anthony