I wish Delta.com would start giving gate information sooner (even now until like T-2 hours it just shows the Terminal not the specific gate). That is why I use flightaware.com which is useful as long as you are not flying Pinnacle/Endeavor or GoJet. Delta/Compass/Shuttle America/Chatauqua all seem to be good about getting gate info on flightaware (SkyWest is also good but they do not fly to LGA). As long as you are not dealing with a flight involving gate D3 or connecting to/from the Marine Air Terminal (except if you are going ORD-LGA-DCA/BOS or vice versa) you should be fine