Millivolt programable heat only thermostat?

[Rothrock42]

@Tony Meola -- Thanks for the suggestion. That is along the lines of what I'm looking for, but that specific one is a bit too complicated. It has controls for Heat, Cool, and a Fan. That means there are going to be a lot of terminals inside and I'm not sure I would be able to hook it up correctly.

Oddly when I search that site for Heat only I'm not sure that any of them would work on millivolt/battery alone and the least expensive one is more than $50. Which seems excessive.

Our society met last night and I talked to the guy who started me on this quest. The ones he is using are inexpensive, but do have to be plugged in. He also said they tend to die fairly frequently because they aren't specifically designed for the challenging greenhouse environment.

Given all the ideas presented so far, I'm thinking that unless the plants start complaining I'll just leave it as is -- at least for this cold season. Next year maybe I'll revisit the idea. Thank you everyone.