We also were suppose to arrive Monday am, but I chickened out and rescheduled for a flight arriving Tues AM. I feel so much better!!! And the kids aren't too bummed since it's only a one day delay. ( I did have to promise to order in pizza tonight though!)
Seems like I've spent hours changing my airline tickets,Poly ressie, towncar ressie and Priority Seatings, but everyone was so cooperative, no extra charges anywhere! My hassle is nothing compared to what Florida residents are going thru, my thoughts and prayer's are with you.
I'd recommend rescheduling now and getting the best available flights before your stuck with whatever's left. From what I could tell WDW will be very busy 9/28- 10/5, had a really hard time finding available flights, PS's, etc.
Good luck to you!