I installed a separate 12 gauge line for my heater, It is connected in the 4x4 box where my black cord terminates and is protected with a 15 amp "fast-blow" fuse inside the box.
Except for the microwave and a/c, all my factory outlets have 14 gauge wire. To make matters worse, they use cheap outlets with push-in connectors for the wire instead of screws.
A few years ago on another camper, I had a 1200 watt grill plugged in my outside outlet. I smelled something electrical burning under the kit sink and saw the push-in wires arcing and smoking. Don't ever plug an electrical heater or grill into a factory RV outlet!
