The only problem with long smokes here in Northwestern NJ, believe it or not, are the bears. We live around a few thousand acres of watershed property that has the highest Bear Population per acre of probably anywhere since they have almost no where else to go in this state that isn't developed.
Consequently they are always around looking for handouts, garbage (or grills and smokers) to get into. I always make sure that I remove and clean the grates and the water tray after smoking, but on these long overnight smokes it can get a bit tense when the bears are around. There is a big (has to go at least 350#) or so male that when he stands on his hind legs is almost as tall as my shed that has scared the cr-p out of me more than once!
Ever since they stopped the bear hunts here, they have no fear of people and just stand there looking at you when you yell at them to try and scare them off. They have actually had three bears break into houses while people were home this year looking for food. I might just bring a side arm out with me when I go to check on things during the night, I'd love to have the chance to take care of him one of and try that smoked bear recipe!
. My biggest concern is that one of these days he will just swat at the smoker and knock it over and cause a fire, or worse, eat whatever I am smoking at the time.