I did some research on uses of corn in the USA. Here's what I found:
World of Corn 2019
Short summary:
Feeding animals for protein/milk production ~41%
Ethanol ~34.5%
Exports: (Probably mostly for the ethanol and animal feed)15.4%
Human consumption ~8%
It is really pretty extraordinary how little of this stuff humans actually eat directly. BEV adoption will put enormous pressure on the price of corn, land prices, and the entire ag economy. The way the US Senate and Electoral college are gerrymandered, we will be seeing no small amount of political pressure following along with the stresses on the local economies.
The other thing to keep in mind is that even considering no deterioration of demand due to BEV ramping, production will continue to increase.
Historical Corn Grain Yields for the U.S. (Purdue University)
This chart shows how the per acre increase in production has ramped along a fairly tidy trendline, but what it does not show is how good modern hybrids have become. Land that was previously not suitable for corn farming is now producing well, so as yield increases on a per acre basis, it also increases the acres planted. With all this in mind, unless there is a huge discovery (bioplastics for example) I see a glut of corn in the medium term and a lot of pain, disruption, and turmoil in corn country.
On a more positive note, I did a little calculation for land use, and one can generate almost 100x the miles with an acre of solar panels vs an acre of corn ethanol, though it costs a bit more to plant a solar field than a cornfield.