Will you need dry ice for just 2 days? If that Igloo is like my small 48 qt, and it is double walled and core insulated, no BS...the regular ice will last that long. The double wall decreases the amount that will fit in it. But man does it increase the performance. At 150 qt I would think you would have a lot of room, even with ice!
To answer your question, no, no chart. But dry ice sublimates at 5 lbs. per day, even less then that in a cooler, and even less then that wrapped in newspaper and placed in a cooler!