Input shaft is spinning, but not all the gears...the gears are what make contact with the oil, and splash it around.
So, with no gears moving in neutral, I don't see the standard transmission oil warming up "to temp" during a 10 minute idle in minus degree temperatures. Engine oil, yes.
As agreed, engine block heater would be best the engine; don't know what could be used for the standard transmission other than some sort of floor heater underneath the transmission.
So glad I do not have these issues in Florida
. And as an added measure, I'm one of those rare few apparently that parks TWO cars in the garage. Imagine that!