My worry would be that every one of those ten thousand riders is going to be eyeing any available plugs at any stops to charge their iPhones. However, if you stay at hotels or other paid places and had two batteries, I imagine it would be highly possible, given the (mostly) flatter nature of the state and some judicious planning as far as Eco mode whenever possible to keep the range up.
On my trip across the Erie Canal last fall I charged at pizza places, libraries and a gas station or two... but it was just me, not those other pesky 9,999 guys as well.
I know there are plenty of hills in Iowa, but in the grand scheme of things you know what I mean by "flatter". It ain't the Rockies or even the Adirondacks!
I'd do it in a heartbeat, sounds like a blast.