If you want to leave on an unattended heat source (and sleeping in the trailer does not define "unattended"), get some insurance on it. Enough to pay for your trailer and everyone else's property that was also damaged. IF everything operates like it is supposed to, it'll be OK. When a safety device fails, bad things happen.
Most RV's have furnaces that are in very close proximity to combustibles. Home furnaces generally are not situated inches from combustibles.
I've been to numerous house trailer fires. They burn fast and are deadly. Almost always caused by a faulty furnace, leaky propane, or electrical at the CB box. Or some idiot using a kerosine heater.