Bastogne is where the Battle of the Bulge still feels close: the Bastogne War Museum on the Bizory road, McAuliffe Square in the centre, and the star-shaped Mardasson Memorial above the town. For US visitors it is often the centrepiece of a Belgium WWII trip — and the roads from Brussels are dual carriageway then winding Ardennes lanes that repay a professional at the wheel.
Allow about two hours from Brussels or Brussels Airport (BRU), a little less from Liège, closer to two and a half from Antwerp. We leave early enough for museum opening times, build in a coffee stop if you want one, and keep a buffer for winter weather on the heights.
A disposition fits the memorial day best: museum in the morning, Mardasson and the Bois Jacques / Easy Company foxholes in the afternoon, then either dinner in Bastogne or a continuation to Henri-Chapelle American Cemetery on the same hire. Your chauffeur waits between stops; luggage and coats stay in the car.