I'll give my dissenting opinion. I would wait to change the oil. You'll be at the 12 month interval when you reach Michigan, but with only 5,700 miles, it should be fine. I believe the oil will still have the ability to protect against corrosion until the fall. I would change the oil then, before the trip out west.
2003 Alpine Coach 40MDTS - 400HP Cummins ISL
Can Am Spyder Roadster