As an Atlantic Canadian, like @Peter the eater, I live in something of a molasses heartland. You know those great big storage tanks you see at oil refineries and suchlike? Here in Saint John, there's one of those full of molasses along the harbour front. Saint John is home to Crosby's, the major Canadian molasses producer.
Stores here sell it in the 4 litre (ie, metric gallon) plastic jug, as well as the more common milk-carton format.