What about making ressies for Crystal Palace or Liberty Tree Tavern around 7:45 or 8pm.
Based on my experience here's what I'd expect your time line to be:
4:15 land @ MCO
6:00 arrive by ME at ASMo (you may arrive 5:30-5:45 but don't put money on it).
6-6:30 Check in, then stop by your room to put down your carry ons
6:30 Wait on bus for MK
7:30 Walking down Main Street!
7:45 check in for dinner ADR
OR you could eat at Narcossee or California Grill and watch fireworks from the restaurant. This might be a more relaxed option. If you have an 8pm ADR You arrive at MK at 7:30, take monorail to Contemporary or Grand Floridian from MK, you should be there about 10 til 8pm. Request a window table when making your ADR, but remember it's only a request, but request again when you get to podium at restaurant. You should be through dinner by 9pm, and may either enjoy your dessert thru fireworks or ask them to hold dessert until fireworks are done.
If you don't get a wondow seat, you can go outside to the walkway around Narcossee to watch the fireworks, and I believe there's a viewing deck off California Grill to view fireworks. I beleive both locations pipe in music from the fireworks.
Hope these suggestions might help.
