A dehumidifier would be counter productive for the plants I grow most of which require very high humidity (70+%). Its a trade off.
I did talk to 2 different greenhouse companies. Electric heat is not doable. My requirements for the amount of heat I need on the coldest nights (which is raising the temp about 30 degrees) with the dimensions of my GH require at least 178,500 BTU's. I currently have 200,000BTUs. In order to get the same with electric I would have to install 240 volt plugs, 50 amp fuses and run about 6 heating units