Won't be too bad, in my experience. Your converter is likely toast, as is your microwave & TV, if the breakers didn't pop in time. Your air conditioner will be fine, as it was turned off at the time probably. Same thing for your refrigerator & water heater. Your 12 volt stuff is probably fine. I'll bet if you replace your converter & microwave, you'll be all good.
If you take a really close look at your wiring, you'll see that it's rated for at least 500 (more like 700+) volts. The wiring doesn't really care how much voltage you're pushing through it. It's much more sensitive to the amperage. With all the open circuits caused by fried & "off" appliances, there wasn't much amperage going through that wiring. No fear of melted wires, just the afforementioned converter, microwave, and TV.
Call your insurance company & tell them your coach was hit by a power surge. Technically, you'll be telling the truth...