Setting up Honeywell WiFi 9000 Thermostats to set temperature based on room sensors

Hey all. I have recently installed a pair of Honeywell WiFi 9000 thermostats in my house - one upstairs, one downstairs. Each controls one zone on the HVAC system. They are both connected to SmartThings, as are contact/temperature sensors in many rooms of my house.

Problem statement is this: Frequently, one or more of the rooms will be much warmer/cooler than the temperature being measured at the thermostat itself, because the thermostat is not necessarily near a vent and is certainly not in a frequently occupied space (both are in hallways). I would like to detect if the temperature at any of those remote sensors drops below or surpasses a threshold and activate the heating/cooling accordingly, until the threshold is no longer exceeded.

I’ve seen a few threads here and there on doing similar things with the Ecobee, but that uses purpose built sensors and I didn’t want a bunch of unitasking devices around the house.

Can anyone help? It seems like it should be a simple integration but I’m just missing something to connect all the dots. I considered using IFTT triggers, but am not sure how to do things like turning the system back off, etc. “IFTT,Until”


I just found the “Keep Me Cozy II” SmartApp and it seems to be exactly what I want!