I would be shocked as hell if that turned out to be a cracked block from the snow.
I highly doubt it.
And I dont think you could hydro lock it unless you shoveled snow and packed it into the intake while it was running.
We have been involved with hydroplane racing since the late 60s and at one time or another every one of the boats have flipped and dropped a red hot engine into the lake.
Ive never seen one thermal shock so bad that it cracked.
Not even the aluminum Buick/Olds 215s
As long as the deadman switch worked, and it wasnt running they didnt even hydrolock either.
And some of those boats sank and stayed on the bottom for a week.
I think you have a "coincidental"
In other words a problem that has nothing to do with the snow bank but you associate it with the snow bank because of vehicular trauma.
Take the serp belt off and run it.
Make sure you dont have a broken motor mount or trans mount.
Look for exhaust and heat shield banging.
Look for suspension parts especially shocks mounts banging.
Make sure the ring gear didnt get packed full of **** and has a little damn rock flying around inside the bellhousing.
Yep, that can happen and it will make you nuts trying to find it.
And, the one everybody misses
Pull the starter and make sure the throwout fork for the bendix hasnt failed and the noise you are hearing isnt the starter gear skipping off of the ring gear.
If all of that fails, I would start looking at a cracked flex plate way way before I thought about it being an internal problem.