I personally have chosen to remove all wires and probes from the inside of the tank.
I have 2 heat pads and 2 separate thermostats. I maintain a second heat pad on the cooler side because it gets really cold here in the winter time and sometimes it gets quite cold in the house.
Right now for example, the cooler side pad is not even on because the temp in the house right now is 74 degrees. Whatever your room temp happens to be, that will be the temp of your "Cold Side." I don't see a need to monitor the cold side temp because I already know it's the same temp as the rest of the room.
I have placed Thermostat probes directly on the heat pads under the tank.
I check my temps inside the tank with a hand held infrared thermometer. I can check anywhere in the tank, anytime I want, just point and shoot.
The "Warm Side" stays around 84 to 86 (minor fluctuations are normal, we'll call it 85).
The "Cool Side" stays whatever the room temp is, right now 74. It may drop to 73 tonight. I have the secondary heat pad set to kick on if the temp drops below 71 on the cool side. It only kicks on during the coldest days of winter.