Heating Solution Found!

Months of thorough research (and patience for season items to come down in price) led to the purchase of this Mr. Heater unit. Now, I am able to--literally-- breathe a sigh of relief because we decided on the indoor propane-powered (clean burning) unit as opposed to the more hazardous Kerosene unit that the boyfriend had pitched. This particular unit is smaller than the one I originally researched, but it is large enough to heat up to 400 square feet! Since our RV only has about 200 square feet of room, I anticipate that the unit will be a comfy hearth for my stone-cold RV. The unit has a tip sensor so that, if by some chance, one of the people or animals accidentally knocks it over, the unit shuts itself off and prevents disaster.
I am pretty confident that it uses propane efficiently. The side of the box says that it can "heat 400 square feet for up to nine days (220 hours)." Of course, that time interval is based on the lowest setting on a full 50lbs. cylinder of propane. Our 50lbs. reserve on the RV should be plenty to run the heater on a mid-level setting all day for the duration of the weekend AND my stove for six meals without sufficiently depleting our propane supply.

Thanks to the local Wal-Mart sale, this heating unit cost us $115.

Specs on the manufacturer's website can be found here.