Here are the following roads that are either closed or DOT Plows have been pulled off the roads. These roads are likely to drift shut.

US Hwy 6 From Atlantic Westward
US Hwy 18 from Emmetsburg to IA Hwy 15
US Hwy 63 from New Sharon to Oskaloosa
US Hwy 169 from Humboldt to Minnesota Border
IA Hwy 3 from Akron to Le Mars
IA Hwy 10 from Sutherland to US Hwy 71
IA Hwy 44 from near Logan to Kimballton and from Panora to Grimes

Many roads in central and western Iowa are “Travel Not Advised”. Those also include a few roads in eastern Iowa as well.
To sum it up, all north south main roads west of I-35 are “Travel Not Advised” which includes I-29, IA Hwy 4, US Hwy 71, 59, 75, 169 and 69.
These roads are also “Travel Not Advised”
US Hwy 18 from Garner West
US Hwy 20 from Iowa Falls West
US Hwy 30 from Cedar Rapids West
US Hwy 34 from Chariton West
IA Hwy 3 from Shell Rock West
US Hwy 218 in Benton County (especially Vinton to US Hwy 30)
US Hwy 63 in Tama, Poweshiek and Mahaska Counties
I-380 from Cedar Rapids to Urbana
US Hwy 65 from Mason City South