A single Butt, 5Lb cooked weight, at 200°F wrapped and held in a cooler stays above 140°F for 5-6 hours with ease. Now multiply that Mass times 40! Shy of storing the Coolers at 30 below zero and in the wind, I would be surprised if the next morning, what 12 hours later, that meat dropped 10°. After all, the center IT, as planned, is 170°, but 30-40% of that meats mass will be closer to 200° or higher depending of the temp the meat is cooked at, as high as 300°F+ possibly, we have not been told the proposed smoker temp.
While I think an IT of 170°F may be a bit low, for the above reason, the IT of that meat will quickly rise and stay there a long time. Essentially, that meat will get near 200°F in the coolers and stay there, or close to it, for many hours after they hit the coolers. It will continue to cook and break down the Collagen from the Carryover Cooking. Collagen breaks down above 130° and does so more rapidly above 160°F. If that amount of meat went in at 205°F, the IT would climb a minimum of 10° and more likely 20-30°F and stay there quite awhile. Not only would the coolers be opened to find the meat already fell apart, the resulting PUDDLE of meat would have the texture of Baby Food.
While Food Safety is a major concern, what some people fail to understand is Meat is a poor conductor of heat. A Butt takes 16 hours to get to an IT of 200° in a 225° Smoker it is not going to rapidly cool into the Danger Zone just because it is no longer being heated. Yes, it to takes longer to heat cold meat than it takes to cool hot meat because the higher energy state of the hot meat conducts heat more rapidly, but Hot Meat takes time to cool and this is A LOT of meat, maintained in a well insulated, quality cooler. Additionally, once the Bacteria are destroyed by heating, the small possibility of re-contamination, taking the meat from the Smoker and placing it in the cooler with clean gloved hands or tools, will result in continued destruction of any new Bacteria because the meat is still well above 140°F and will stay there more than long enough to maintain safe meat. Since many people will be eating this Pork, all involved need to pay extra attention to cleanliness. Any handlers must handle the meat with clean gloved hands, rewashing and re-gloving after touching any contaminated surface, face, hair, other food items or contact surfaces. As an added precaution the coolers need to be. Clean and Sanitized with a Bleach solution of 1 Tablespoon Bleach per Gallon of water and allowed to air dry. Lastly the cooked meat needs to be placed in the coolers and left Shut! No sampling, No admiring the work or showing others how good they look, No looking to see if some walked away. Serving this large quantity of Pork will result in large quantities being exposed to air and temps can drop below 140°F. Some type of Hot Holding equipment should be used to maintain the meats temperature at 140°F or higher.
If anybody would like more info on The Thermal Properties of Meat and other foods and how the above is valid, below is some reading and the Formulas to calculate how long meat will stay hot for yourself...JJ
http://forums.egullet.org/topic/40548-science-of-the-kitchen-cooking-meat/
http://pcfarina.eng.unipr.it/Public/Termofluidodinamica/Utility/Tabelle Alimenti.pdf