So, quick update:

1 - Replaced the top of the Exo Terra tank, which then allowed an 8.5" dome, which then allowed a 150W CHE.
2 - Turned on baseboard heat so that the room has some level of higher ambient heat (though it is a hard space to heat well from a single source, other than the wood stove)

Results: The habitat is maintaining temps of 82 degrees without issue (falls to 80, then turns on, back off at 82, usually hits 82.4) Its currently 68 degrees in the room, so we're getting a 14 degree differential now and the habitat is not struggling to get to 82, does so with ease. SO , I think we have temperature figured out. The only remaining issue is that the shady parts of the "cool" side are 73 - 74 degrees - but anywhere the light touches (Lion king) is upwards of 85 degrees surface and the ambient as measured in the middle of the tank, under shade, is 82.

Humidity - well now, still working on that, but I have an idea. I found a small wooden-looking ball that is a scented oil humidifier. Without scented oils obviously, it sends a wisp of most air up about a foot and seems able to get the tank to 65 - 70% after some minutes. So I ordered a humidity controller and we'll see. I actually found three different small humidifiers, so I'll try them all - different configurations and water reservoirs.

Quote Originally Posted by Craiga 01453 View Post
And you definitely don't want temps that high. I never let mine hit 90, nevermind 95+. I aim for a hot spot off 88.
I calibrated the hot spot again and I am now reading 90 in most areas with that particular small spot at 92 -93.