Most of the time, the freezer's circuitry will have a built-in delay that won't let you cycle faster than x amount of time. If you want to be on the safe side, I would suggest that you enforce a 5 min delay in addition to the hysteresis that you mention.
You're likely going to get fussed at for keeping your keezer so cold, but I'm with you. I like to keep mine in the same range too if I have a light colored beer on tap (which I usually do).
What are you using for your temperature sensor?