Okay this is what I've found: Under of Ordinance No. 1563/2007 of 11st December, is considered sufficient income for subsistence the following amounts: € 6,360 / year for the first adult € 3,189 / year for another adults of family € 1,908 / year for each member less than 18 years. Not bad actually, just over €318k in VWRD (2% yield) will give you that in dividends if you're on your own. Add another €159k for a spouse and €95k for each child.
If money is tight you could always take more risk by holding high dividend stocks or ETFs, but you do need to be very careful.