The quietess most efficient space heater is an electric blanket or electric bed pad.
They are typically in the 100 watt range, come with a thermostat or thermostats, place the heat where you need it most and use little energy.
When you wake you can use what ever you like to heat the trailer. We typically turn on a thermostatically controlled electric heater. It has two ranges, 800 and 1500 watts. It cost $10.
Generally once we start breakfast that's enough to keep us warm between the coffee pot, toaster and bacon and eggs.
In really cold weather we occasionaly turn on the propane