msturtz wrote:
Keep in mind that your dash heat will not heat the basement only the furnace. Most Gas rigs do not have heated basements and most DPs do but that isn't always the case. Some gas rigs do have heated tanks.
I think the OP had the furnace on - not reliance on the dash heat. And it's not true that gas units don't have heat to the tanks. The duct work for the furnace is run in such a way that allows heat to the tanks to keep them from freezing. On our entry level coach we've travelled in sub 20 deg temps and never had an issue as long as the furnace was running.
So yes to the OP, fill your FW. Even without heat it would take days of sub freezing temps to get that frozen. With your furnace on you should not have an issue. I would prep for trips in the winter when we lived in MD, often days before we would leave in sub freezing temps. Set the furnace to 48 and it kept things from freezing without using up a ton of lp.