First things first..
We hate being cold so we decided to take the insulation extra serious this time.
As our insulation material we used x-trem which comes in 2cm and 1cm thick sheets. Nearly everywhere we used 2cm. Just on the bridges and inside the doors we used 1cm. With big pots of glue and a
knife Ferdinand stuck all the bits on the roof, sides, and floor of the van. He then filled all the holes he could find. This should be enough insulation to camp out and be comfortable in -20