Thanks for the thought.
They called AAA, but said they can't commit to any time frame because of the weather.
We were in Tiffin for my mom's families christmas and my wife and I left at 5pm, and it took us 2 hours, driving 10-30mph under the posted speed limits for most of the time because the roads are pretty slippery up north.
My parents left at around 8pm, and obviously didn't make it too far.
Thanks again. Much appreciated.