Bit of an Old thread but I thought I’d share my solution.
We live in a property with no gas, all electric panel heaters and boiler, as such managing the temps in each room is a bit of a nightmare - especially if you forget to turn things off!
It seems there is no real solution from firms such as NEST, HIVE or ECOBEE for those with none traditional central heating, as such I did the following. Note we use apple homekit though as of writing this there are other solutions.
Each heater is plugged into an EVE Elgato plug, these allow for remote control and you can see their Realtime usage in KW/H
Each room has a Phillips Hue motion sensor as they also have a temp sensor, At the time of putting this all together HOMEKIT was the only solution to allow the temp sensor form Hue to be read, Alexa and such are unable to read it.
Using an IOS app called Home+ each room is given an automation such as, If the temp drops below X then turn the Living room radiators on. If the temp is equal to OR greater than X then turn the living room radiators off. You can dial in further detail such as only allowing this to run if people are at home, between set times or when you’re a certain distance from home.
There are other solutions now using things like home assistant,. I know people think this is probably a bit too much effort but during the colder months our electric bills have really come down!