Many years back I found myself unknowingly driving on a interstate in Iowa that was closed due to a snow storm. I was all by myself, and never saw any closed gates or signs.

In hindsight I should have tried to find a hotel along the way, and continued the next day. Being before cell phones, that could have been easier said than done.

I'll 100% agree that moving from a closed major highway to small backcountry roads during a major snow event is a bad bad idea, especially considering he was driving a camper.