You won't need a ton of heat, even with the cold northern idaho temps in the winter. A heater or ceramic reptile bulb would do the trick. Some people use hairdryers too. You may also want to consider using a brew belt that is strapped onto your fermenter, or a heating pad that is directly under your fermenter for better efficiency in your heat transfer. It's more efficient to heat the beer directly than it is to heat the air around the beer.
Whatever you do, just be sure that your temp probe is either in (via a thermowell) or strapped to your fermenter so you are measuring the temp of the liquid, rather than the air.