While Georgia's 6th Congressional district is much more Caucasian than the state as a whole (GA-6 is 72.4% vs Georgia as a whole being 59.7%), Georgia 6 is also much more highly educated than the state as a whole: 56.3% College Graduation rate in GA-6 vs 35.5% College Graduation rate in Georgia as a whole. This suburban district is exactly the place where Democrats will need to capitalize on an anti-Trump backlash if they want to win back the House in 2018.
Democrats probably shouldn't be all that competitive here. That being said, Trump has maintained historically low approval ratings for such an early point in a Presidency. That coupled with the unique demographics of GA-6 and a less than stellar Republican candidate. Karen Handel ran for the Republican Gubernatorial nomination in 2010 and came in second behind Nathan Deal by 0.4%. In 2014, Handel ran for the open Senate Seat in Georgia and came in third behind Perdue and Kingston. This being said, she did win her 2006 election in Georgia for Secretary of State. While Ossoff the ideal candidate, he is no Quist.
Montana brought an interesting set of circumstances that we don't have in Georgia. Quist and Gianforte were both spectacularly terrible candidates. Gianforte's biggest blunder could be considered assaulting a reporter on the eve of the election. Quist still lost because, 1. Montana is really that red, 2. 73% of ballots had already been cast before election day, & 3. Assaulting a reporting probably encouraged some voters that were heavily behind Trump to come out and support Gianforte.
So, should Democrats be considered the favorite in GA-6? Well, it is ~3 weeks off. But, the race certainly appears to be sliding away from the NRCC and Karen Handel. A Handel win would not be a surprise, but it would suggest Democrats will be unable to win back the House in 2018 if the national climate doesn't worsen for Republicans. (It certainly could. The climate being this bad this early in a Presidency is not a good sign.)