It would be unfortunate to not finish your thru-hike on the summit of Katahdin, which is an incredible experience.
You can ovoid the crowds by camping away from the shelters. Most people who complain of the crowds are packed into shelters like sardines… go figure!
After mid-April the number of hikers starting thru-hikes rapidly diminishes. In '04 I started on April 23. I had two different week-long periods where I didn’t see another thru-hiker on the AT! There were a number of days where i didn’t see a single person.
Besides camping away from shelters, another strategy is to find ‘voids’ on the trail where there arn’t many hikers. Thru-hikers are like a ‘train’ of sorts, and there are almost always a few empty cars, especially in the back of the pack near the caboose, or up front near the engine.
That being said, you might find that the people you meet, including fellow thru-hikers, are just as important as the solitary ‘wilderness’ experiences. Its nice to have a balance. Sometimes i cook dinner at a shelter with others and then move on a couple miles to camp by myself. The friendships that form during a thru-hike are very deep - perhaps because of the shared experience and harships that everyone goes through. Thru-hikers and war veterans are quite similar in this respect.
I think that you could start in late April, avoid the crowds and still enjoy the wonderful finish atop Katahdin without rushing too much.
Happy Trails!
freebird