Ender 3v2 and extruder fan

I started printing some PETG where I need a hotend temp of 240 - 250C. The Ender 3v2 should be able to handle this. To my surprise, I was not able to get above 230C. I am printing in my basement where the ambient temp is 15C and this seems to be the issue: even though the hotend is running at 100%, the fan sucks in too much cold air and cools the hotend too much.

To my surprise, I found out that the Ender 3v2's fan seems to be constantly running. How do you deal with this?

And yes, I know 15C is too low, I am already planning a case for the printer with a auxiliary heater to keep the ambient temperature more stable. But nonetheless, a fan control would be nice!