Just speaking from a practical standpoint, you and the bike need to be a tuned machine, in sync with each other, so you know the gearing, how it handles at speed and under braking, and – most importantly – how well the saddle will match your own personal sitzplatz.
Remember too that riding the 60 miles or so between Sergeant Bluff and Ida Grove is not easy, as it takes you through an area considered to be a part of the Loess Hills. I seem to recall from previous years that while none of them are particularly mountainous – usually only a couple hundred feet high at most, they are a series of rolling hills; any elevation you gain you almost immediately give back on the back side. And since the Hills generally make up the first fifteen to twenty-five miles of the western side of Iowa, they just keep coming and coming.
Fair warning — a day of riding under these conditions could be challenging, even if the bike is set up to your tastes and likings. And if it i̲s̲n̲’̲t̲, you could be signing yourself up for such a level of self-inflicted torture that martyrdom would seem pleasant in comparison.