And don't make such ludicrously humongous batches as several gallons at one; what the fuck are you, a *factory*? Single-gallon batches will keep you in the region of not-too-exhausting numbers of times you have to fill that quart jug.
BTW, I seriously suspect the *main* reason for the difference between using a five-gallon container and measuring it out one cup at a time would be the accumulated sloppiness at the edges; you'll hardly be bothered with sifting it into each of those almost a hundred cups, and leveling each of them off with a straight-edge. Natural sloppiness repeated eighty times over will probably introduce a lot more imprecision than the exaggerated bug-bear of "packing down".