There are some crazy people who ride back the next day...but that's a totally unofficial ride. They call it MARDO (mad @ss ride do over). There is also the PALM ride (pedal across lower MI), but I think that is also West-to-East. I imagine it has a lot to do with prevailing winds. Only sadists want to risk riding 150ish miles with a headwind the entire way.
I think a lot of folks from the Eastern side of the state carpool over and/or take the bus back that night, then drive back home the next AM. If you wanted to find people to travel with we have a FB group for connecting with other riders, ODRAM Riders Hub.