We will use Black Powder this evening as they're the set Peter is most used to, him being a very infrequent wargamer. It should also guarantee we get a result by the end of the evening. I've played Mollwitz a few times over the years, using both BP and Honours of War and its not always been a smooth ride by the Prussians to an historical outcome. The game is a (hopefully) finely-tuned balance between superior Prussian infantry facing decidedly uninspiring Austrian infantry, and numerically and qualitatively superior Austrian cavalry.
Terrain wise, apart from Mollwitz and a couple of other built up areas the cloth is completely open, on the basis that the roads, streams and marsh are all covered by deep snow and/or frozen solid.
I shall report back tomorrow.