https://electproject.github.io/Early-Vote-2020G/IA.html
Dems have returned 407,668 ballots, GOP 276,188.
Those numbers arent particularly bad for Iowa compared to 2016 stats. Trump would never have won the state (as he did by 9%) if he didnt get a tremendous percentage of the Democrat vote. Take a look at TargetSmart. Based on their well-regarded voter modeling, Republicans are actually doing better there now than last time. Even just looking at the registrations of people who have already voted, Republicans have 32.1% of the current vote vs. 34.8% for 2016. Thats not really what Id call crushing numbers.
Okay, then Iowa us lost. Is that better?