If you have PreCheck and you have already checked your bags at the resort before you leave, you can get from AoA to the gate in about 85 minutes pretty easily. Your flight will likely begin boarding at about 0740, and you want to be there at least at that time. So you ought to be OK if you're out of the resort and on Victory Way at 0610 in this case, but no later.
A coupe caveats - while Osceola Parkway is a more direct route, exiting the property via Buena Vista / Epcot Center Drive / 536 will take you right past a couple of convenient gas stations to refill the rental, both just past where 536 crosses 535. (Street view in Google maps is incredibly convenient for checking these out ahead of time.) Also, I would allow an extra 15-20 minutes if you are not familiar with the roads in the airport, as missing a turn may require you to take another loop around. Finally, you will not move as quickly as I do if you have smaller kids in tow. Figure to add another 15 minutes in that case.
With all these tidbits, as the saying goes - "you do the math".
And one thing you might not think about - be sure you know ahead of time where the gas fill-up is on your car, and how to open the latch. You'd be amazed how often people get flummoxed by that.