MCT is 35 minutes, so it's legal. The arrival time is gate arrival (not landing). Yes, there can be variable times in getting jetway attached and door open. But it generally shouldn't take more than a few minutes. DL pads their flight times a bit and looking at flight history, the flight often arrives 15 minutes or more early. That said, when there was weather in the area recently, it was 16 minutes late. The good news is you will probably not encounter gate or airspace congestion with current amount of flying. The flight has also been arriving at A gates recently and the DCA flight often seems to use A gates as well. The main variable will likely be possible weather. If you are comfortable with possibly having to overnight in ATL, I would probably risk it under current circumstances.