We use this heater
http://www.laskoproducts.com/heaters/model_5900.html from Lasko. If it is cold at night, we set it near the base of the steps and aim it toward the bedroom and it blows a steady stream of warm air that direction. And my wife will sometimes use it during the day if she gets cold. Very quiet and stable. Wife also uses it at home in the bathroom for extra heat.
Got it at Sam's several years ago, but have not seen one there lately. Been wanting another so I don't have to move this one from the house to the 5er and back.