Although most people can't afford a dual proportional thermostat which can be almost $300, i would at least get an on/off or proportional thermostat so you have at least something to control the heat pad.
UTH's are notorious for going on a rampage and having the temperature spike extremely high, then dip down during the night. Getting a Thermostat, whether it be a Johnson, Ranco, Helix, or Herpstat, they are all great choices for your situation and would really help you keep tabs of temperatures especially when your gone or on vacation.