Our Georgetown Class A has the Arctic Pack (or, as FR insists the "artic pack"). Hate to tell them that "artic" is UK slang for an 18-wheeler, short for "articulated lorry".
IMO it's a really dumb system design. The heating pads are 12 volts DC and draw 7 amps each. My MH has two on the grey tank and two on the black tank. According to the manufacturer's documantation, the non-adjustable thermostats turn the power on when the tank gets down to 40F and keeps them on until the contents have reached 60F. Who needs to heat up the sewage to 60 degrees?!
I expected the system to be similar to the "frost-stat" system in houses. I also worry about the effect on the tanks of pushing 160 Watts into a relatively small area of the tank surface if it happened to be empty. I was so perturbed by the possibilites of problems with the system, I've disconnected it. We don't use the RV in very cold weather (that's what the S&B house is for!) and it's rare for us to get low temps much below 25F and almost never does it stay below freezing all day in winter.
If you need to "cook" the sewage to prevent freezing, I'd be tempted to disconnect the original thermostats and install the kind used on house plumbing systems that turn on around 34 degrees and off again at around 40. If I remember my high-school physics class correctly, dissolved contamination lowers the temperature at which water freezes, so the holding tank contents might not freeze up until 28F or so.
Frank and Eileen
No longer RVers or FR owners