Unless you are arriving at rush hour, there is really no reason to avoid I-4. However, if you are arriving at rush hour, you can take the 417 (Central Florida Greenway) south. I believe it does intersect somewhere with I-4 but I'm not sure exactly where. You should see signs for it though. 417 is a toll road and you can expect to pay at least $5 in tolls if not more.
Also...if you have a cell phone, you can dial 511 and get I-4 traffic information to check if there are any backups. The areas to worry about are "Orlando Metro" and "Attractions" if you call. I'm not 100% sure if it will work for people whose cell phone numbers are not local though.