The Hiawatha train is the (or one of) the Chicago-(Sturtevant)-Milwaukee commuter lines. It runs quite often, but no idea if it allows bikes. If it allows bikes..and you can get off at Sturtevant, then there's a couple places to camp a few miles NE of the station and you can pick up a MUP close to the campgrounds..that MUP will take you all the way to Sheboygan Falls on about 90% dedicated bike trail. MRV has my RWGPS routes..
https://amtrakhiawatha.com/amtrak/schedules.php