You know, I've wondered this many times myself...
The "danger zone" for meat is between 40*-140*F (4C-60C) that is the most commonly referenced temperatures.
"Bacteria that cause food borne illness multiply quickest between 4°C and 60°C (40°F - 140°F). The Danger Zone is this temperature range in which bacteria and spoilage bacteria grow quickest. Lower temperatures prevent the bacteria from growing to dangerous levels. Temperatures above 60°C will kill the bacteria."
What I've often questioned is, many times cooking pork, I'll take it to 200*-205*, if I'm fairly careful to wrap the meat quickly in a clean environment, what baceria is there to grow? I know that germs and bacteria is all around us and there truely is no sterile envrionments. In fact there are many good bacteria that are needed in everyday life.
I am no expert in this field, but I will tell you I have taken 200+ degree food out of the smoker, double wrapped it, put in the cooler with several thick towels, and 10 hours later they are still too hot to hold on to. Sliced and ate them and they were the ternderess pork I've ever had. No one got sick or even felt bad.
But you have to do what you are comfortable with. To be safe I'd keep a probe in it and stay above 140, which if you cover it well, would easily be 6 hours.
Best of luck this holiday weekend!!
