I had no luck looking for a passive temperature controller. This looks like the lowest current thermostat I could find:
https://www.amazon.com/GERI-Single-C...erature+switch
<5mw when the relay isn't active.
I'm thinking of pairing it with one or two of these:
https://www.ebay.com/itm/DC12V-5W-6x...688:rk:16:pf:0
And to wrap the whole thing in a thermal blanket of some sort.
Thoughts?