I just made my pie crust and put it in the fridge to chill/rest. I forgot to add the sugar and salt, can it be saved or do I need to start over?

There IS salt in the butter already...hmmmmm

I suggest you make another batch with the correct quantities for the pies you will be serving to party guests.

I'd freeze the incorrect batch for another time and possibly for a dish that isn't as sensitive to the properly seasoned crust (like cheese twists or something else).

I would add it sooner rather than later! You will end up with a tougher crust (from overmixing), but easier to incorporate when it's more rather than less pliable. Personally, I would start over.