Ditto on the bedroom floor duct coming loose. Caught it in our inspection prior to taking delivery. The Redwood mechanic removed the basement wall to reach the duct. Not sure if this would work for you in the Texas cold however I have worked in the basement with the lights on during our Midwest bone chilling days. The basement is heated so with the side doors down it is cozy inside (block one door to prevent any chance of latching). I just set all my stuff/junk on the ground while working in the basement area.
Bob and Carol - Lees Summit, MO,
2016 Silverado 3500 HD, High Country DRW diesel, 3.73 gear ratio, long bed, 25K Reese Elite removable hitch with 2013 Redwood 36RL with 17.5" H-rated tires and MOR/ryde heavy duty shackle links and bushings; 6.5 KW gen