Hmm, DFW is talking about blizzards, cold winters and ice storms. Probably not Florida :-) though the same principles apply. Sounds to me like it'll take a lot of BTUs to keep warm and protect the property (frozen pipes cause a huge, nasty flood mess when they burst).

I believe the Mr. Heater non-vented wall mount units are legal under many U.S. building codes. (Not in Canada, though.) Oxygen sensors and a ruby catalyst apparently knock the CO hazard way down. So if enough propane could be safely stored, that would be enough to heat a basement room. If upper-level water pipes could be depressurized and gravity drained, and RV antifreeze put in the sink/toilet/shower traps, that could go a long way to preventing water damage.

Idea: there are low-scent versions of kerosene available. Worth a try. Be aware it will gel up in extreme cold.

Idea 2: Could the kerosene heater be placed on/in/near the fireplace, so you could open the flue slightly and lose some of the exhaust fumes? Just a notion.