Or better yet.. After getting the warning that running the heater on factory wired outlets in my RV might not be the best of ideas (Hot wire smell I invested in a pair of contrasting (Color that is) 15/20 amp outlets, These are the ones with the "T" shaped neutral, will take either a 15 or 20 amp plug.
Some 12ga and a couple of breakers.. One for each outlet
Now I have two outlets, Connected by 12ga, properly bent around a screw and tightened down well each fed by its very own breaker, Nothing else on that breaker.. No more hot wire smell.
That said, In my case that was an easy job, Direct access to all wire paths was simple. This is not always the case.
Home is where I park it!