A US liquid pint is equal to about 473 millilitres, since there are one million bytes in a megabyte we can assume that there would be one million pints in a megapint.

1 megapint = 473 176 473 millilitres
≈ 473 176 litres
≈ 473 cubic metres

A megapint of red wine would be enough to fill a 20x10 metre swimming pool to a depth of 2.36 metres.