Worried about van insulation

Too little insulation will make for some freezing nights, but can you go overboard and overheat your van? Or am I overthinking this. I want to know everyone’s thoughts about van insulation

I don’t think you can overheat with insulation. I looked at every type in the world before settling on acoustic batting. Fiberglass breaks down over time, denim gets wet and sags, etc. It’s hard to make a final decision but the acoustic stuff worked great for us.