The only problem I've had using space heaters is this: Motor home and Traier wiring often uses "Quick Boxes" these are not really up to a long term 12 amp load.. And I started smelling HOT WIRE.. Others have had outlet failre (so have I but that was a different issue)
On low or Medium (900-1000 watts max) you should be OK. but on HIGH (1500 watt) I would worry. IF you smell hot wire, SHUT IT OFF and post..
What did I do about it?
Well on my coach it was an easy job so I added a couple breakers and ran 12 ga wire.. one from each breaker... To proper house type 15/20 amp outlets in a proper outlet box.. Wire bent around a well tightened screw.
WOrks well.