I travel for business so have been on many flights/airports and the reports on DIS are accurate--even early morning flights, what are usually non-busy days, security is PACKED! We arrived 1.5 hrs early for a 7:25 am flight and barely made it to the gate after waiting in security....personally I would rather wait in the airport than miss my flight. Other options include PP suggestion of hotel at the airport OR you can try to change your flight (depends on airline what the fees might be) if you want to leave later in the day.
That has been our experience with early morning flights as well. Our last flight we had an early departure - 7-something. MDE picked us up super early then we made a few more resort stops before heading to the airport. Security line was crazy - the longest I have ever seen it. We made it through, went to the restroom then we were boarding. I thought it seemed too early to leave but in reality it was just barely enough. Other times with flights later in the day we seen to have plenty of time to spare but you never know what could come up. Better safe than sorry imho.