I helped an OP here with total shore tie power failure in his 30-amp Class C. Turned out the wire nut splices where the flexible shore tie met the solid house wire had burned out. We were able to troubleshoot it over phone and email thanks to Winnebago's on line wiring diagrams.
He later told an RV tech, who said it's common for RVers using electric space heaters to have that happen. Asked if our OP was using portable electric heaters and he said "Yes, Two."
We can run two 1500-watt heaters in our 30-amp Class C using separate interior circuits. I actually added a dedicated socket to allow that.
Just wanted to reinforce the idea that two portable heaters can take a 30-amp coach to its max.
50-amp offers the power capability, but outlets are likely to be on 15-amp branches so your load will have to be divided up between two of them.