I recommend that you travel far enough south of Atlanta to stay south of Hudson Bridge Road, which is exit #224 on I75. Even though you will be traveling the next morning in the opposite direction of most traffic, that exit is pretty much the beginning of heavy congestion traveling northward.
At exit #221 (Jonesboro Road) there is a Courtyard by Marriott and a Fairfield Inn & Suites.
Exit #218 (Hwy20, Hwy 81, McDonough-Hampton Road) has a few more choices, including a number of restaurants. Hilton Garden Inn, Holiday Inn Express, Super 8, Econo Lodge, Comfort Inn & Suites, Hampton Inn, Best Western Inn & Suites, Howard Johnson, Country Hearth Inn.
Both of these exits are considered to be in McDonough, GA. It is a decent & safe area. You will be well-positioned to zip on down to Disney the next day, probably in 6 hours or so, depending on how often you stop and how fast you drive!