Our 2016 Montana Legacy has done fine at 24 degrees supplementing the furnace with an electric heater and we were very comfortable. I have a temp probe mounted between the holding tanks and they never got close to freezing running the furnace maybe 10 minutes per hour. I don't have much to compare it to but it stays a lot warmer than our 2007 Laredo did in the same temp. Also our camper has over 300 nights spent in it and about 18,000 miles with no major issues and has never been back to the dealer since the day we bought it. Good quality or just luck? Who knows.