If you get stuck in creeping traffic with no fans, open the windows and put the heater on full blast.
The engine will now be happy stuck in traffic all day.
You will be miserable though.
The heater also bypasses the thermostat too.
One thing that p1sses me off about the VAG temp gauges, is they lie. At least on TDi's.
The temp gauge is not the engine temperature, it is what the marketing department forced the engineers to program the engine management to send to the gauge.
That reassuring, perfect, sign of a quality engineered car, that steady 90 degrees that the gauge is showing you, is actually any coolant temperature between 70 and 105+ degrees.
If you drive with VCDS connected, you will see this.
You are denied the ability to get early warning of problems.
If I could work out
how to program it out in the engine management, I'd be in there like Flynn.
https://www.vwaudiforum.co.uk/forum/showthread.php/96923-Vag-com-engine-coolant-temp-reading