Hi Jennifer,
Never say never!
Although
Character Dining is very popular, that isn't to say that you won't be able to snag a couple of dining reservations before your visit - even if it is only 4 weeks away.
I would recommend that you search for any available Character Dining reservations for the dates of your stay using the
online dining reservation system on the Walt Disney World website or if you prefer, you could call and ask a Cast Member to check on (407) 939-3463.
If nothing is available, don't give up hope, cancellations take place all of the time so just be sure to keep checking daily as you never know your luck.
If all else fails, there is nothing to stop you from just walking up to any of the Character Dining restaurants to see if there are any available dining reservations but I believe that your best chance would be to try to get some before you arrive.
Wishing you a magical trip filled with memories which will last a lifetime!