Sleeper Compartment Overheating

Some of us have both an APU and a Webasto bunk heater. The Webasto sucks cause they don't regulate. It is either "on" or "off". So you wake up sweating in the middle of the night... Turn it off then wake up freezing.

2 of my truck had this setup. This one has a Webasto with an actual temp reading. It's better than the one I had in the past.

That's exactly what I am familiar with. Every truck I have had (4 total, including 2 loaners) have this exact setup. Just as you described, have to turn it on before going to sleep and turn it off when getting to roasting point. Unfortunately, it's usually wake up to freezing again.

APU:

Auxiliary Power Unit

On tractor trailers, and APU is a small diesel engine that powers a heat and air conditioning unit while charging the truck's main batteries at the same time. This allows the driver to remain comfortable in the cab and have access to electric power without running the main truck engine.

Having an APU helps save money in fuel costs and saves wear and tear on the main engine, though they tend to be expensive to install and maintain. Therefore only a very small percentage of the trucks on the road today come equipped with an APU.