Heating control with sensors

Hello, I am new to automation and right now I dont own any device except Hue hub and Nest mini.
I want to make smart home with heating integrated. My vision is simple: lights,plugs and thermostat with sensors. My house dont allow much more.
I live in two floors house with central heating(middle europe so its water heating with one heater). current old thermostat is on floor 1.
I am looking for a thermostat I can use on floor 1 and sensors that I can place anywhere in the home,specially floor 2 as thats colder.
All of this would be connected to some Smart home application.
In the Smart home application I would like to be able to set up weekly plan, maybe even monthly plan for heating,lets say per hour. Also marking of holiday, I get i would have write those dates but thats fine. Just an option to put somewhere dates that will use “weekend regime”.
And here comes the tricky part: it would heat base don temperature on all sensors, like if any sensor is below 24°C then it would turn on heating,if all sensors are over 26°C it would turn off heater.
Ecobee is not sold in Czech Republic, Netatmo is but dunno how to incorporate multiple sensors. There are some zwave thermostats,cheap, and zigbee sensors that could be used but then I dont know how Homey works with sensors and temperatures,if its possible to se t flow like i would like to have.
Thanks for response.

So when u have an average house, with like 6 rooms, u want the heating to turn on when 1 of the rooms comes below 24. How do u prevent to turn the other rooms to like 28?

I want to start with thermostat and one sensor and then replace radiator valves to smart ones (with sensor). More less its all about 2 sensors only, one on each floor.