Well, I decided what the heck, why not. So I pulled the back off the fridge to expose the compressor and what-not, looked for the bottom corner curve & figured that would be a pretty safe place to drill as no coils should be in a bend like that, so either I was right or lucky, no issues with the drill! Ran the power for the light and the bulb for the temp controller.
So this is one of those analog controllers that changes states on temp fall and opens at set point. (kills power once the temp is reached). Now what do I do if I want to use the heater? I'll need it to stay closed until temp is reached (rise) and 'then' open. Can you wire the switch backwards or do you have to buy a switch that opens on temp rise?
I guess worst case is just to use this controller until this fall when it turns cold again and just build a true 2 stage controller. ugh!