Given my experience with my BMW - I'd be inclined to let it warm up for a half-minute to a minute in cooler conditions for a couple of reasons:
- Shifting the gearbox, even in "cool conditions" (between 50-65ºF, 10-18ºC) starting out can be notchy. With fast-moving traffic, you need to keep up, shift quickly and get moving.
Idling in neutral would seemingly allow fluid to be splashed around and helps the initial shifts quite significantly.
- Engine response when cold is delayed and exasperated:
E.g., Starting off is fine, but when you go to shift, the RPM is sort of "hangs" and drops slowly. Slowing down, there is a delay before the engine starts to slow down, and it is usually a slight "jerk" that accompanies.
In other words, it just feels "weird" until the temperature gauge gets out of the blue area and the engine comes out of the cold-start regime.
- Shifting the gearbox, even in "cool conditions" (between 50-65ºF, 10-18ºC) starting out can be notchy. With fast-moving traffic, you need to keep up, shift quickly and get moving.
Idling in neutral would seemingly allow fluid to be splashed around and helps the initial shifts quite significantly.
- Engine response when cold is delayed and exasperated:
E.g., Starting off is fine, but when you go to shift, the RPM is sort of "hangs" and drops slowly. Slowing down, there is a delay before the engine starts to slow down, and it is usually a slight "jerk" that accompanies.
In other words, it just feels "weird" until the temperature gauge gets out of the blue area and the engine comes out of the cold-start regime.