https://community.home-assistant.io/t/smart-thermostat-2-0-blueprint/478348

smart-thermostat.yaml

blueprint:
  name: Smart Thermostat
  description: 'Based on your window sensor this automation turns the thermostat on
    or off. You can also specify the time that is needed to switch the state.  In
    order to avoid heating in summer, you can specify the weather entity and your
    winter temperature. Read more: https://community.home-assistant.io/t/smart-thermostat-2-0-blueprint/478348'
  domain: automation
  source_url: https://gist.github.com/AlexanderBabel/69c3b996a66b3a132cafadcbac4140cc
  input:
    window_sensor:
      name: Window / Door Sensor Group
      selector:
        entity:
          domain: binary_sensor
          multiple: false
    window_delay:
      name: Window / Door Sensor Delay
      description: Time the sensor needs to stay the same after change to trigger
        the automation. This is done to avoid retriggering. (Default = 5s)
      default: 5
      selector:
        number:
          mode: box
          min: 0.0
          max: 3600.0
          unit_of_measurement: seconds
          step: 1.0
    weather:
      name: Weather
      description: Specify your weather to get the current outside temperature from.
      selector:
        entity:
          domain: weather
          multiple: false
    wintermode:
      name: Wintermode
      description: The ouside temperature needs to be below this to activate wintermode.
        (Default = 16°C)
      default: 16
      selector:
        number:
          step: 0.5
          min: 0.0
          max: 150.0
          unit_of_measurement: °C or °F
          mode: slider
    wintermode_delay:
      name: Wintermode Delay
      description: Time the outside temperature neeeds to stay above the wintermode
        temperature to turn the heating off.
      default: 30
      selector:
        number:
          mode: box
          min: 1.0
          max: 86400.0
          unit_of_measurement: minutes
          step: 1.0
    thermostat:
      name: Thermostat
      selector:
        entity:
          domain: climate
          multiple: false
trigger:
- platform: state
  entity_id: !input window_sensor
  to: 'off'
  from: 'on'
  for: !input window_delay
- platform: state
  entity_id: !input window_sensor
  to: 'on'
  from: 'off'
  for: !input window_delay
- platform: numeric_state
  entity_id: !input weather
  attribute: temperature
  below: !input wintermode
  for: !input wintermode_delay
- platform: numeric_state
  entity_id: !input weather
  attribute: temperature
  above: !input wintermode
  for: !input wintermode_delay
action:
- choose:
  - conditions:
    - condition: and
      conditions:
      - condition: state
        entity_id: !input window_sensor
        state: 'off'
      - condition: numeric_state
        entity_id: !input weather
        attribute: temperature
        below: !input wintermode
    sequence:
    - service: climate.set_hvac_mode
      data:
        hvac_mode: auto
      entity_id: !input thermostat
  - conditions:
    - condition: or
      conditions:
      - condition: state
        entity_id: !input window_sensor
        state: 'on'
      - condition: numeric_state
        entity_id: !input weather
        attribute: temperature
        above: !input wintermode
    sequence:
    - service: climate.set_hvac_mode
      data:
        hvac_mode: 'off'
      entity_id: !input thermostat
  default: []