We live in northern Indiana and have driven to WDW nearly 20 times. Here's my advice, especially at this time of year: do NOT take I-75 through Georgia! After multiple horrible experiences with road rage (ours and others) and several trip with hours-long stops for accidents and construction, we will NEVER take that route again.
We now take I-65 through Alabama, I-10, and SR 27 through rural Florida. It is slightly longer, but is beautiful and stress-FREE! We always stay overnight in Dothan, Alabama. My anxiety-prone husband is now a happy driver with no white knuckles. Worth the extra 1/2 hour to avoid the stress and the delays/stoppages on I-75, especially when 1/2 the Hoosier state is going to Florida.