Thanks! I'm back in Mankato now, dressing the avalanche of email Monday will bring.
There have been a number of people going through the ice this year already. People don't think this through. It's especially dangerous on a river because the current can pull one away from the hole they fell through and trap them under the ice.
I did drive out on a lake when I lived in SD. After three weeks where the "high" was -20°F, it seemed safe enough.