My 320 acts the same. When very cold the early upshifts seem quite delayed and the downshifts are earlier and more pronounced.
That is why I let her warm up for five minutes or so if below 20 degrees.
It does make a difference.
I also notice a slight "Whine" from the front (engine) just after starting in the same conditions but it quickly disappears.
Best Wishes,
Ron Y
2000 E320