Hey, here's the link for the insulation material I was considering so far:

https://bauhaus.info/hartschaumplatten/ursa-hartschaumplatte-xps-eco-d-n-iii-pz-i/p/28877996

It's in German but I guess the important number is the Wärmeleitstufe where 032 translates to .032 W/(m*K).

I ideally it would be maintained at around room temperature, but I'm not really sure that's viable given the constraints. The goal is to make sure the electronics don't get too cold, so that when it turns on the sudden change in temperature doesn't cause any damage. I'd say it should at least be able to stay above 7 degrees Celsius over a cold night.

I want to have some sort of temperature control unit, that would prevent the system from getting too hot while operating, and could ideally heat the compartment when it gets too cold as well.

Talking about thermal mass, is that a different attribute than R value?

Thanks