It's hard to get opinions as to what will effectively "take out the chill" as different people have different temperature sensitivities, and are comforted by different amounts of heat. Someone may say that a particular heat source is enough to make them comfortable, but it may not be enough for you. Or it could go the other way: someone may say it's not enough, but you might think it's just fine. As an example, DW and I can never agree on temperatures, so we compromise: she's cold and I'm too warm.
The heat strip will put out about the same amount of heat as a hair dryer. So if you think that'll be enough heat for you, then go for it (the heat strip, of course, the hair drying is not designed for long term use!) You have to decide if the convenience is worth the cost (a portable heater is the same heat, but less expensive.)
For about the same amount of electricity, a heat pump will put out a lot more heat than a heat strip, but still not as much heat as a propane furnace. Of course, the heat pump costs a lot more than a heat strip. And while a good residential heat pump may work down to about 30 degrees, the RV units seem to cut off around 40 degrees - mine must have an outside temperature sensor, because once the outside temperature drops to below 40, the heat pump shuts down and the furnace automatically takes over.