Just remember that the fermenting product will generate heat on its own....I tend to average 8-10F rise in the ferment temp itself. Had one batch hit 18F rise and I was very concerned about cooking my ferment....ended up giving it an ice bath. During summer our house typically sits at 72-74, spring/fall 68-70, once winter hits we maintain thermostat at 70 but will use a space heater.
I do agree that you should check the temp range of the yeast you plan to use, as they play such a vital role. People use space heaters, brew belts, heating pads, etc. when dealing with cool temps. I have read that some build insulated ferment cabinets.