Darren,
March is a long way off and many years have had excellent snow and almost empty slopes. To guarantee snow at that time of year in Europe a resort height of 2000m or higher is normally the best bet.
That said I was in Bansko in March of 2007 and had excellent snow and fairly qiet slopes.
Even if the weather is starting to warm up then, if a good base has built up there can still be some good skiing to be had.