I have found that by covering the glass doors on my AP cage with a blanket at night keeps the inside temperature a few degrees higher...
Would the same work for a rack?

I'll be moving back to the Netherlands in two years and temps can get pretty low down there.

Of course with other snakes apart from BPs the temps can get pretty low.

What rack would keep the inside temperature the highest compared to other rack systems? Anybody got experience with different ones?