Hi,
I think the problem is there is no way for anyone to know the answer to your question without knowing the ambient temps in your room.
I think it would be worth trying the UTH on its own once you have insulated the tank.
Put the body of the acurite in the cool end to get the cool side ambient and the humidity and put the probe under the substrate under the warm end hide - this should be the hottest part of the enclosure your snake will be able to reach so make sure it is not any hotter than 95f then adjust everything else from that point.
If the uth can keep the cool end at the right temps on its own then that avoids the problem of the CHE draining the humidity.
If it doesnt then you need to use the CHE and adjust the tank to compensate.
It sadly is just a case of set it up and let it run for a good few hours before checking to see what it gets to.
dr del