They go most places a standard rental car can.
Hello and welocme to the RTA forums !
I have done RV trips but not through Michigan. However I have nevr found them to be too restrictive and that includes the mountains in Colorado. The one thing you should consider is that an RV is rarely a cheaper option than a car and hotels by the time you add all the associated costs with RV rental up. This would include higher gas consumption, campground fees and mileage charges, but if there are 4 or more adults sharing the cost who would want sperate Motel rooms then it becomes more even with a car and Motels. First and foremost though it should be a Lifestyle choice.