Sounds like you are doing what I have been considering. Having to get up at 3am for a 6am flight (with a stop as there are no nonstops from MKE) and not reaching Negril until 5pm has become so physically exhausting. I've been looking at Atlanta and Charlotte with the idea of flying there the day before, getting a hotel for 1 night and catching a mid-morning nonstop to Mobay.
Are there any other suggestions for airports that fly nonstop from the US east coast?