I like to go 230 for 12-14 hours, but like D said you don't need smoke the entire time, I don't count the warm up hours either... so I really mean longer than 14.
The closer you are to below boiling (212 degrees) the less moisture you loose, but of course that takes longer. In Kansas City some of the smoke houses will smoke your meat for you for 14-16 hours at 190 degrees.
We trim off the fat where it's too think the night before, rub it and wrap it up, then smoke it the next day.
