What is the daytime temp and humidity range where you are? There is a temperature/humidity logger on the market that looks like a USB memory stick. It works great for troubleshooting housing temperature issues. I can't find a link to the one I have but here is something that should work. https://www.amazon.com/Freshliance-T...3&sr=8-13&th=1

For fogging, I have found that if I put the lens against the housing window, it will fog. If I move it back a couple mm it cures that problem. I also install a housing vent that incorporates Gor-Tex, it keeps the inside of the housing at the same pressure and the outside. https://www.gore.com/products/gore-a...or-electronics

Hope this helps. Please report back on your resolution.