CARD MOD setting height when using entity filter

I am pretty new to this, but am pretty happy with my project. Now comes the fine tuning and I can’t figure out a solution to this problem.

My thermostat shows just fine (left in the picture) and sizes perfectly. Now I figured, I only want to see the thermostat, when the heating is on. So I am using a “entity-filter” to show the thermostat. This works nicely, but: The thermostat does not fill the container it is in. HA_CARD and a height of “100%” or “auto” do not work as expected. Setting a fixed height works sort of… When resizing the browser, at some point the thermostat just does not fill it’s container.

What is the trick here? I am stuck and have searched for literally hours to get this to work!

type: entity-filter
  - climate.thermostat_wohnzimmer_heizung
  - heat
  type: thermostat
  fill_container: true
  entity: climate.thermostat_wohnzimmer_heizung
    style: |
      ha-card {
        height: 100% !important;

Seems I just had to reduce the font size for “Biotonne” etc back no normal and everything seems to work now!