We have driven through Asheville to the north woods of Wisconsin many times and have used several routes. Most GPS devices would route you through Chicago to I-65, to I-64 in Louisville, to I-75 in Lexington, to I-40 in Knoxville.
We don't like driving through Chicago or Louisville. Here is the route we would take.
I-39 to I-74 in Bloomington, to I-275 around Cincinnati, to I-75, to I-640 around Knoxville, to I-40.
That route is about 50 miles further than the one I described in my first paragraph.
The climb from Tennessee into North Carolina (Pigeon River Gorge) is long, but gradual. There are steeper grades on I-75 form Kentucky into Tennessee.
To avoid the majority of the climbs (but not Pigeon River Gorge), you would need to go through Nashville.
I-39, US 51, I-74, I-57, I-24, I-40.
That would add another 60 miles.
Tom
2015 Meridian 36M
2006 CR-V toad
3 golden retrievers (Breeze, Jinks, Razz)
1 border collie (Boogie)