Surely wearing arm and leg warmers with short sleeves and legs is much the same as wearing longs?
I went out on Monday, at 8 degrees, with swirly winds at 35 mph. Had neck thing folded on my head, thin long finger gloves, base layer, windproof soft shell, tights and overshoes. Neck thing was removed after 2 miles and rest of body just got warmer and warmer as I rode further.
Could quite easily have ditched the base layer and overshoes and swapped the gloves to fingerless. Short sleeves maybe too, it was that mild even with the wind.