rgatijnet1 brings up an excellent point. Maybe, just maybe, John, you might get very lucky, and find that this was just a rock or something came up and punched the hole in the oil pan. In which case, all your engine may need is a new oil pan and 6 or 7 quarts of oil. It does seem kinda strange IMO for an engine with only 37k miles to grenade itself??
YOu say you heard a bang, and saw a lot of smoke. Where did the smoke come from? Out the pipes, or from underneath? If it came from underneath, not out the pipes, I'd say its possible that the pan just got a hole punched in it by something.
Has anyone dropped the oil pan off the engine yet, John? Or possibly put a wrench on the crankshaft, and see if the crank will turn without any 'bad' noises?
Drop the oil pan, see how things look in there. I think you'll be able to tell very quickly once the pan is off, if the engine grenaded or if something from the outside punched a hole in your oil pan.
I'm sure you thought of this already, but, would it be possible for you to just park the MH at a semi-permanent site for a while, and live in it there until you can save up the $$ for the engine repairs? I saw quite a few folks doing just that (living full time on semi-permanent sites) at Carolina Landing in SC, where you used to stay quite a bit.