Here's the response I got from ICBC... turns out as I've seen many times people offering advice don't have the correct information.
Dear Mr. Koperski:
Thank you for your March 3, 2017 emails to ICBC Feedback regarding coverage for a vehicle sinking while driving on an ice roadway.
There is no exclusion for driving over a frozen lake. If a vehicle accidentally sinks through the ice, and the driver did not intend for the vehicle to sink, it would be considered a Collision claim.
The frozen lake surface would be considered the roadway with a body of water underneath. A sinking vehicle would collide with the roadway and the water.
There is the potential for environmental damage to the lake if a vehicle were to sink and leak fluids. The vehicle’s third party legal liability coverage would respond if a policy holder is held legally liable for environmental damage to the lake.
I hope this information helps. Thank you for writing.
Natalie Aktas
Customer Relations Advisor
G268953