20 miles is a long commute. I would suggest you also have at least a couple of shorter rides that you can drive to and leave your car. There are many reasons for this including getting a late start, having to get home quicker for appointments etc etc etc.

Bimodal commuting will go a long way in keeping you motivated.

You will work out the eating thing as you progress. I would start with toast or cereal at first and maybe eat a good breakfast at your morning break.

That's a huge generalization to make. I'm in good shape, and I find my body performs better with food (given sufficient time to digest). That being said, I get up and ride 17 miles almost every morning before I come home and eat breakfast. So I don't really "need" it, but my body works better with it.

Ah, there's the rub. Time is of the essence. For me it wouldn't be worth it to get up earlier, eat & digest food, ride to work at a faster pace, and get there at the same time than just sleeping in and ride to work without eating. My pace is about 20mph, so I doubt there's much to be gained there anyway. I'd much rather have the sleep.

I do the multi-modal commute thing often. It works well.

Get up earlier (I wake at 5:30 now), ride 17 miles and THEN ride to work. You gotta be kidding!

I used to eat before riding, but have been making a change in that for the past few weeks.

Before I leave I eat a banana. I hop onto the bike and ride in to work, where I unscrew the lid of my thermal bottle and drink my (still warm) oatmeal. Works great as for recovery as well. My ride is about 16 miles one way, which is slightly less than an hour.

High fiber oatmeal with a tablespoon of ground up flax seed, some coffee, and a banana or some other piece of fruit every morning before my 20 mile commute. No problems even on days when I do intervals.

some train without nutrition - sounds nuts to me - but each his own. I liked ot eat before I train 1 - 2 hours then have a simple carb right beforehand. Today about 1.5 hrs before my GYM session I had 2 fozen blueberry waffles and a small chicken cutlet. I skipped the raisins right beforehand.

I wake up at 5:30 and eat a big breakfast (for me). I hate eating at that hour, but if I don't eat, I'll be famished before 9:00 and won't have another opportunity to eat until lunch. I don't eat before my ride home, however.

I get up much earlier now that I'm a little older, so I always have time to eat a light breakfast. Cereal, fruit or a P&J sammie w/coffee and I'm ready to roll.

I don't feel right heading out on an empty stomach, especially with coffee sloshing around...

A pint of tomato juice before you go then pack a banana and some sandwiches with Vegemite for crib when I get to work.

Bowl of cereal. Sometimes an apple or something else when I get to work.

Typically one doesn't need to eat immediately after they wake up, your body keeps blood sugar at a certain level for a while after rising. You can exercise this way for a short time and it may be more comfortable than riding on a full stomach.

If you don't have time to sit and eat the meal, cook your breakfast the night before, toss it in and ride to work.

Try to keep breakfast sugars low and to avoid a sugar spike at work after, eat mostly things like eggs, oatmeal, milk. No fruit juices, eat the fruit instead - the fruit's fiber buffers the sugar absorption.

Oatmeal is the breakfast of champions.

Bowl of shredded wheat typically. Some honey for flavor.
I ride 9.7 miles to work and it takes 30 minutes, I'm hauling as fast as I can to make it a workout.
I decided once this week I'd do it before eating anything. I went out and felt the same as if I'd eaten.
The endorphine buzz kept me from feeling hungry though and I forgot to eat my breakfast once I got to work. Had it with lunch (cottage cheese and yogurt with shredded wheat) and drank a bunch of water through the day.
That day i decided to go the long way home to stop at the LBS so it was a 22 mile evening ride. I only had water with me, didn't eat a snack before leaving work. I started to feel a little weaker on the last 6 miles. I think it could have happened anyway, but I thought the main thing I did was change my eating routine.

I have a fairly strong stomach though so I can eat up and then hit the road within 5 min and feel relatively fine.