You didn't say what city you're leaving from and what city you're heading.
2279 miles - If going to southern Michigan from San Diego, take I-8 to Phoenix; I-17 north to I-40 east. Then I-44 at Oklahoma City to St. Louis then I-55 north to Joliet, IL and I-94 east into Michigan.
2433 miles - If going to the Upper Peninsula of Michigan from San Diego, take I-8 to Phoenix; I-17 north to I-40 east to Santa Rosa, NM. Then Hwy 54 to Meade, Kansas to Hwy 400 to Wichiga. Then I-35 to Des Moines, Iowa and I-80/380/151 to Madison, Wisconsin and north to Green Bay, WS and north to the Upper Peninsula and Hwy 2 across to Mackinac Bridge.
Full-timed for 16 Years . . .
Traveled 8 yr in a 2004 Newmar Dutch Star 40' Diesel
& 8 yr in a 33' Travel Supreme 5th wheel