Being DTW based, I've never heard of Terminal 2 or a gate with a number anything close to 217.

But more so, I have never known gate information to be available for a flight 4 months out. Most of the time, you'd be lucky to know the gate 12 hours out.

If both your flights are on Delta and neither is a barbie jet, chances are they will both be in the McNamara A Terminal. 57 minutes is easily doable. As other have said, 90 minutes on the return for clearing customs might be close.