I really don’t need too much heat, unless it is a Log Fire on Winters Night, then I can quite happily toast myself.
My listening space has been known to be 8-10 Celcius on a Winters Day and creep up to 18 -20 depending on how long the Room is occupied and Valves Amp’s are Powered On. With the Heating on as well the room can got to 24ish.
In the coolest Temp’ the Cart’ can sound a little off, but this can be a combination of both Valve and Cart’ attaining warmth and hitting their sweet spot.
I only know off Cart’s going Heel Heavy when their Suspension Wire has lost its optimised tension.
I recommend letting a trusted US Third Party Cart’ Service offer a assessment and correction if need be.