I'll leave this picture up for an hour and then delete ...........

To answer your question download the picture and then look at the metadata.

I snapped that picture yesterday as the hummer was hovering (in flight). Notice the camera on the metadata and the mm on the lens. The lens was a kit lens 18-135mm set at 85mm.

Notice the other settings ........ cropped sensor, 1/500, F/10, 640ISO.

I was 5 feet away from the little guy and yes, I cropped in big time in PP, thus the grain but never less you can take nice snaps of hummers with your camera and lens.

The 6D isn't the best choice for moving targets ..........

But I've snapped a few hummers with mine. Here is what I would do ...........

You actually are a tad hot already.

You need more DOF. F/4.5 isn't going to do it. On the lens your using I'd set to F/11, raise your ISO to 2500 - 3200, double your distance from the feeder. Focus on the feeder when they swarm. I'd also get your shutter speed up to at least 1/320 if not higher.

When you do your PP crop in 100%, that retrieves the double distance you gave up. With 20MP you can give half of it away. But backing up and giving yourself more space will increase your DOF. you might find you can go wider once you back up a bit.