Making Nest a bit Smarter

So I have a Nest thermostat downstairs which works pretty well but I have an old house that can get pretty cold upstairs.

I have some temp sensors in a bunch of rooms and I want to have a bit more control about the Nest calling for heat.

I was essentially looking at a schedule (on top of the Nest schedule) that looks something like
6am - 8am - If kitchen or any of the bedrooms are < 19C then heat
8am - 4pm - If kitchen or study < 19C then heat
4pm - 10pm - If kitchen or any of the bedrooms are < 19C then heat
10pm - 6am - use Nest schedule (sets heat to 12C)

I have the Nest API stuff setup and I believe there is no way to force heating on the Nest other than setting the temperature so I planned on setting the temp to say 28C when I wanted to heat and 19C when I didn’t (that is the default on the Nest)

When is the best way to achieve this? Do I need to create separate on/off automations for each time period with calls the nest API or is there a more elegant way of doing this?

I do not have the answer, but this exact use case was one of the reasons I chose ecobee over nest.

With ecobee, and its sensors, you could ask ecobee to set cool/heat based on average of part (or all) of the temp sensors. You could also even ask ecobee to tune the cool/heat based only on sensors that detects motions, so if ecobee sees people only in the kitchen but no one in any of the bedrooms, then the focus would be on that kitchen only.

One trick i use is to pair automations with a calendar integration (e.g. google calendar) . I set a #hashtag as a filter that gets turned into binary_sensor which I use to turn on/off any particular automation. Then you can go schedule when you want various automations to be on and adjust them as you see fit. I use this for a light schedule or motion detector schedule, for example.

Yeah if I was starting again I probably wouldn’t go with Nest but the Nest is coming up for six years old now and was the first smart home device I bought.

I do have this working with six different automations (having figured out to use conditions to have AND logic for to turn the heat off only when all the temps are above 19C).

Doesn’t seem very clean as I have the same code in multiple places and if I decided to change the 19C to 20C then I need to go into quite a few places. Also setting the Nest to 28C to force it to call for heat seems a bit dirty.