I have hauled quite a bit of meat from IAD-BWI to BVI(a place, not an airport) for charter sailing trips. Use a coleman type cooler and about 5-10 lbs of dry ice in single block for 40 lbs of meat. tape the cooler shut. lots of tape. The dry ice keeps the meat frozen for about 4-5 days.
Have also flown game from Texas to DC the same way.
Anyone want a source for dry ice in the BWI-IAD area send me a message.