Cold Weather Operation of Fresh Water Drain

We will be traveling from Michigan to Arizona in January. Even if we follow the warmer southern routes we will have a few nights below freezing. While we will be heating the BH 3055RL while traveling and at night, I am concerned about the fresh water drain valve hanging down below the underbelly.

One of the members (2010augusta) suggested the addition of another fresh water drain inside the underbelly as a way of reducing the risk of cracking the PEX hose due to freezing.

My proposed plan is to cut a 4" flap in the underbelly to access the PEX hose. (This flap can be re-closed with velcro or duct tape.) By using a tube cutter inside the underbelly, I should be able to cut the existing tubing. Using a Sharkbite ballvalve, I can reconnect the PEX tubing without having to get PEX tools up inside the underbelly. The Sharkbite works just by pushing the hoses together.

The operation of the new arrangement would be:
1. Open both valves to drain the fresh water tank when no heat for the underbelly is available.
2. Close the valve in the underbelly and open the outside valve when heat to the underbelly is available.
3. Open the underbelly valve during warm weather months. Open and close outside valve as needed.

My questions before I cut the access flap for the underbelly are:
1. Is the drain line a line with 90 degree elbows or a straight hose from the tank? (I can jiggle it, so I think this is longer hose with elbows)
2. Will this allow me to keep water in the holding tank while traveling from cold to warmer climates?

I have a Sundance MK2900 but I think the setup is about the same. I would let it freeze. In a worse case senario that piece of pipe would crack and you would have dripping to the outside and then you could fix it then but I really do not think it will be an issue. I would be more concerned about sealing up the underbelly and keeping it warm. When we head south from Ontario we take a 5 gallon jug of water for flushing the toilet and leave the trailer winterized till we get closer to non freezing temperatures.

1. It wouldn't really matter - siince it would be above the underbelly either way.
2. Yes.

FWIW: I moved my Cyclone from Douglas to Buffalo, Wyoming last March - in freezing temps - with all 3 lines and valves hanging below the underbelly and did not have a problem with any of them. Doing as you describe would insure no problems. Go for it!