Thanksgiving week is a possibility for the big stretch of US 20 between US 71 and IA 4 to open. (Fort Dodge Messenger)
This would be the last major relocation for US 20. From 71 west, new lanes would likely closely parallel the existing route.
Side note: The new segment is listed in the article as being 26.2 miles long. There might be a “marathon” theme in the making there.