If there were going to be any effects, the area around and south of Macon is where I would expect them. But I think I-75 should be fine.
We evacuated from Miami to Madison, GA for Irma last year (NEVER again!). The surface areas south of Atlanta away from the expressways got hit hard by Irma, even though the winds didn't get above 40 MPH. The rain soaked the ground, a puff of wind, and big trees came crashing down everywhere -- taking power lines with them. Our home in Miami (with hurricane-force winds on the strong side of Irma) had power restored before our sanctuary in rural Georgia!
But there aren't any big trees right next to I-75, so you should be fine. Have a great trip.
(And that reminds me...I still owe our next door neighbor dinner at Joe's Stone Crabs! We were busy last year with recovery and never got to do it. Gotta get on that as soon as Joe's reopens Monday...)
