I have been saving coins now for about 4 years. I have 6 giant plastic Coke a Cola bottles. I reckon each bottle could hold 20 litres if full. To give you an idea of size, each bottle almost comes up to my hip.
Bottle 1: I put all 1 cent, 2 cent and 5 cent coins in. It is three quarters full.
Bottle 2: I put all 10 cent coins in. It is half full
Bottle 3: I put all 20 cent coins in. It is just over half full.
Bottle 4: I put all 50 cent coins in. It is one third full.
Bottle 5: I put all €1 coins in. It is just under half full.
Bottle 6: I put all €2 coins in. It is roughly one third full.
I am not sure what I will do now, keep going and force the government to mint new coins or call into a bank and see the horror on the tellers face.