Only one way to know, and thats to train, practice, and compete. You can sit in and draft, making that 22mph a lot easier, which is different than if you're taking turns pulling. im in about the same boat, wondering the same thing, but there isnt much way to tell, short of one of those athletic tests that test your VO2 max and what not. Sounds like you've got a decent start, keep at it!

Try getting a trainer to ride at those odd times, like late at night. its boring as hell, but it helped me get quite a bit of riding in, since i dont like the rain(always rainy in olympia). Get a heart rate monitor, find your zones, and do some training. Ive heard suggestions about "the time crunched cyclist" and a few other books. theyre on my list to pick up. I need some help getting a structured training plan set up, and you might need it too.