I've noticed something interesting in the past few months. The Boveda packs in the three humidors that I keep in the bedroom refuse to dry out. I'm not complaing, mind you, but they still feel "fresh". I put the packets in the humidors the end of November 2013, almost 5 months ago I've got four 69% packets in each of the two 100-ct Tuscany humidors, and two in the smaller Yukon/Capri 50-ct. The humidity, according to my Xikar hygrometer, in the three humidors is 66%, 67%, and 66% respectively.
By comparison, I find myself replacing the Boveda packets in my other humidors in the den and living every two to three months or so. The humidity stays in the same range and the humidors are of similar quality as the ones in the bedroom.
I would say I open the humidors equally, maybe 2-3 times a month. The only real difference is the location. Our bedroom is generally a few degrees cooler than the rest of the house during the day, and the adjacent "walk-in" shower gets used two or three times a day so there are brief periods when the ambient humidity may be a little higher.
Could the few degrees difference in temperature make that much of a difference?