My new TT is a 30 amp trailer and we enjoy driveway camping, especially on the week-ends, even when it's freezing outside. Found out the new camper struggles to keep things warm with just the furnace, but we've always used a ceramic heater to supplement. Found out, with this trailer, longer, slides, taller, it still does not quite "make it". So we put a second one in the camper.
Found out 2 heaters on one line blows the 15 amp breaker in the camper. But found out the television did not 'blow'. So now we plug one heater in one circuit, and the other heater on the other circuit with no more blown breakers in the camper, and still run everything else comfortably. Since it's winter, we don't use any water, so no water heater.
You can run 2 heaters, just make sure they're on 2 circuits INSIDE the camper, and you're still limited to only 30 amps total.