Almost the same thing happened here in August 2003. We were lucky - CEE BEE was in the shop that day so we had a loaner car when we got stuck in a couple of feet of water in our flash flood here.
But..........a guy that had bought a XF at the same dealership we did had to have his towed in after it got caught in water. They had to total his - it was a couple weeks old when that happened!!
I cringe when it rains here - because it does not rain often - but when it rains - it floods!!!

Good Luck with your drowned XF. That is a very sad story. I hope the insurance company will take care of it for you. Be sure to keep us posted.