Quasmodo's suggestion to avoid Atlanta altogether sounds like a good idea.
If you decide you have to drive thru Atl, then I would not take the 285 bypass - all thru trucks are diverted onto 285. The HOV lane thru downtown on 75 is the way to go (2+ passengers). Atlanta rush hours run from about 6:30am to 10am, and 3pm to 7:30pm.
You mentioned your dog; if he/she needs a break, Kennesaw Mt Battlefield Park is not far off I75 about 20 miles north of Atl, and is very dog friendly with lots of walking trails, and even a pretty good little museum.
" Successful investing involves doing just a few things right, and avoiding serious mistakes." - J. Bogle