In a room that cold, a UTH will not raise the tank heat nearly enough. You will Likely need to add a CHE, probably a 100w, and you also VERY LIKELY need to raise the room temperature at least to 65 degrees.
See this is my concern. I will have to see what temp we can get it to over the next 2 days then look at switching. We do have plans for a CHE when we move it from faunarium into Vivarium in a couple of weeks.