Fantasmic Dinner Package in December?

[Mommy Poppins]

We are going to WDW 12/4-12/13. Thinking of trying to see Fantasmic on Monday, 12/8. Do we need the dinner package or will it be easier to get seats because it is supposed to be a slower season???

We would like to eat at PTC and I know that restaurant is not included in the dinner packages.

Thanks for your opinions.