Hi Edwin,
I don't know exactly how a Torque is plumbed. But generally the Pex line to the fresh tank is on the off-door-side. The drain valve is usually slightly in front of the front axle and is teed into the fresh tank line a few inches above the valve. Generally, the line between pump and fresh tank will connect on the front surface of the fresh tank, near the bottom of the tank.
In sub-freezing weather, the water in the drain line that sits below the coroplast, and above the drain valve, will freeze because it's not heated. Even if insulated, that only slows the transfer of the little bit of heat in the water. It won't take long at 10 F to freeze that exposed section of hose. The ice can wick up the line into the tee and block the line between the fresh tank and pump.
The heated underbelly will help prevent this if you're running the furnace enough. But even so, as temps get colder, the underbelly heat isn't always enough. You'll need heat tape on the fresh water line, as well as a heating pad on the fresh tank. You may also need to keep the pump warm by hanging a heat lamp nearby.
We have an owner-written
Water Systems Winter Usage Guide that covers all this and more.
