Well I'm still a newbie myself but heres my little exp. I started with a tank a month ago and my house temps are just like yours (its winter heat is expensive) I could not properly heat and maintian humidity in the tank. the best i got was to put the heat lamp and UTH on hot side and a small 5 gallon tank size UTH on the cool side. Go to walmart or Lowes and get an AcuRite indoor outdoor thermometer (seems to be the popular one here and works good for the money) for like $11. and you will see that those little round or stick on ones are not very accurate. I also put the water bowl directly over the UTH on the hot side to aid in evaporation and covered about 3/4 of the top of the tank with a damp towel. Plus I have a 20 gall humidifier running in my house and could not get humidity over 40% in the tank. Now i have a tub set up and a thermostate, heating is no issue and humidity is actually a little high (still working on bringing down).