For a train of them one has to wait+wait. But, just for 3 weekends around Xmas, FROM 20/12 till 4/1/15, ONLY SAT and SUN, overnight, to ANTwerpen (19eur)-Eindhoven (14 eur)- to Dusseldorf (29 eur). can combine with some shrewd planning in IC-trains to points further in DE for same price.
If...