Originally Posted by
SuperVoid
Last February 17 I drove from Munich via Nürnberg and Magdeburg to Hannover. There was heavy icerain most of the way but the roads were clear (not on the A96 Munich-Lindau, though).
The car rental equipped me with an Audi A4 2.0 T Cabrio

with winter tires so all went very well in the end. Never felt unsafe

So, anything can happen with the weather, but on the motorway you should be ok ^
It really depends on the situation. If there is heavy ice-rain or snow-fall, then road service might be very busy. Hence it is possible that there will be lots of snow on the Autobahn.
I remember that I had once one out of three lanes free of snow between Frankfurt and Würzburg a few days before Christmas.
Additionally, there are usually major problems when first snow of the season comes. It is always surprising how little some drivers are prepared (technically & mentally) for winter conditions during the first days of snowy road conditions.