Ok so I just called my main Mech to find out about what Dip$#!& told you, you can’t actually “Blow your Motor” like that, Potentially Crack your block maybe(That’s my thought due to the extreme differences,) but probably only if there’s already a crack started. Give the Devil his Due though maybe because when you crack your block it’s almost as good as Blowing your whole motor. We’ve had it happen to at least one of our vehicles, but never by driving it into mere cold water, I mean what the Hell are Jeeps designed to do? But they said the same thing you discovered, mostly it those G-D’ed electrical systems. Again personally from being a Jeep afficienado, and having to many “Mechs in the family” As long your engine gets air for it’s combustion, and your electricals are safe from shorting via water infiltration, you can go through all the none solid (As in not ice, or snow 😀 ‘disclaimer because you know someone will try it!! Lol!!) Water you want too!! Which is why you see Offroad vehicles with those really stupid(And Fugly) looking high exhaust pipes!!!
But I’m glad to hear you’re both OK, But now how do you deal with this tomorrow?
edited to add:
Unless the water is high enough to actually get down into the engine, and kill its lurication, not because of temperature.