Considering your reason for cancelling, I'd cancel Maya Grill. Pepper Market is a great food court. If you can't get into MG w/o a ressie, you aren't missing that much. After Maya Grill, my choices would be as follows:
The meals you have that I absolutely wouldn't cancel are:
Mama Melrose w/Fantasmic (Keep it for the reserved seating, during a busy time.)
LTT night of MVMCP (I'd keep this one above all others. Not really for the food, but the atmosphere is absolutely perfect for MVMCP.)
CRT (Great choice for Christmas morning.)
Next on my list to keep would be:
Jiko
California Grill
Both for food quality
HDDR (Unique & fun experience)
Afternoon Tea -Garden View Lounge (Another unique experience. If you have something similiar offered at home, you could scratch this one. Otherwise I'd keep it.)
Last tier would be:
Coral Reef (No real reason for not choosing this one. It just doesn't seem as special as the others do to me. However, I'd choose it over the two restaurants below.)
Le Cellier (IMHO, highly overrated on the DIS. Our meals have been very hit or miss there.)
1900 Park Fare (Only because you already have a Cindy meal that day.)
Whatever you decide, I hope you get everything you're hoping for.
