Just a note on packages vs booking separate reservations and Disney Travel Co (WDTC) vs other travel companies.
With WDTC if you do have to cancel your package, the ENTIRE package is cancelable/refundable, meaning that your tickets will be cancelled & refunded, too. This can be a big benefit if you travel long distance and/or you don't know when you'll be able to reschedule OR if this may be a once in a lifetime trip.
Disney tickets bought separately through Disney are NOT refundable. Yes, they still retain their value, but I'd rather just be able to get my money back.
With third party vendors (for hotels, tickets, or packages), you just need to be very, very careful and scrutinize their cancellation and refund policies, especially wrt park tickets. Yes, they may be a few bucks cheaper but some of them include nonrefundable tickets.
We always use WDTC for our WDW & DLR trips. Especially WDW since we drive cross country. And we were easily able to reschedule our last WDW trip to more than 30 days out when I had a medical issue arise. If we had then had to cancel that trip we would have gotten a full refund.