I have a 3rd gen Nest learning thermostat that I installed specifically because it 'supported' additional temperature sensors. Shame on me for not understanding how they worked, but they're basically useless. You can set a "safety" temperature, but for whatever reason that ONLY takes the reading from the active temperature sensor into account. To me, this is a mistake.
I live in Minnesota, but I'll assume other places have similar issues. In my case, I have a "tuck under" garage. It's attached to my house, but it doesn't need to be heated to the temperature that my house does. Doing that would be a complete waste of energy. However, since it's technically inside my house, there are water pipes that run through my garage ceiling. Normally, none of this is a concern because I have ducts from my furnace in there, but they're purposely inadequate because heating and cooling a garage like this the same as your house is incredibly stupid. What this means in my case, is that for most of the winter my garage will run around 40 degrees when my house is at 68. At night, I actually turn my furnace to 55 because I prefer to sleep cold, and it saves energy. Again, for much of the winter, this isn't a problem because my garage is insulated and the temperatures tend to stay relatively constant no matter what the outside temperature is. However, there are many days where the temperature outside will drop to crazy low numbers. When that happens, my garage temperature will drop below 40. Basically If my house is at 55, and the outside temperature is -10, my garage will drop below 32 and my pipes will burst. So I'm back to having to either crank the heat in my house to compensate, or use an electric heater in my garage to artificially act like a temperature sensor and keep the garage temp around 40.
I installed this thermostat hoping to solve this issue permanently. However, I can't use the temperature sensor in my garage, realistically, because the thermostat only allows the lowest temperature to be 50 - which means my house would actually be warmer at night than it is in the day. I'll be hot, and I'll be wasting energy.
So, my feature request would be to either allow a lower temperature setting on my thermostat so that I can set my garage to a more reasonable 40 degrees, or better yet - use all of the available temperature sensors in the house for the safety temperature feature (which, to be honest, is what I expected when I bought this).
