Hey, my first post here, long time lurker.
I have a 21'
fiberglass class A motorhome. Vixen RV.
I have both a hydronic (coolant) diesel heater, and a common diesel air cabin heater. The cabin heater is by far my favorite utility. Last night I boondocked in Western New Mexico at an abandoned rest stop. It dropped to 22 degrees, but my cabin heater kept me warm and toasty all night.
I have the 5kw model, but a 2kw may be enough for the Scamp. Diesel heaters produce an awesome type it heat. It's not a dry heat, nor does it make moisture, just a nice moderate heat.
I haven't measured fuel consumption but when I'm in cold weather for a week, it will use about 2 gallons of diesel fuel (not running all of the time).
Lastly, diesel is the most safe of any liquid/gas fuels.
Hope this helps.
-Dwayne Domi (google me)