Table to show indoor temperature for binned outdoor temperatures

Hi there,
I have a central heat pump and would like to investigate any room for optimization.
For that purpose, I would like to build a Chart/Table, putting in relation the minimal indoor temperatures with binned outdoor temperatures. I am collecting both in an InfluxDB and have access to it in Grafana.

The result shall by something like this:
Outdoor 20°C: Indoor 21°C
Outdoor …
Outdoor 6°C: Indoor 22°C
Outdoor …
Outdoor -5°C: Indoor 23°C

This would ideally let me see, that I can lower the heating hurve from my heatpump.
I hope it is clear what I am trying to achieve. The indoor temp I want to use is from an “uncontrolled” area, so where the heating valve is permanently open. That way, I can rely on the heatpump output directly affecting the indoor temp in that area.

What I am struggling with is, to set this up as a Chart/Table as I am clearly a beginner here :-).
I appreciate any clues towards this.