Can you prep a day in advance?

I'm planning on making Pot of Joy next week for a dinner party. Do you think you can do any prep work for this a day in advance, like hollowing out the veggies or even stuffing all the veggies and storing them in the fridge until bake time? Or do you think it would compromise the quality of the dish too much?

Thanks! Looks so delicious. Can't wait to make this.

Megan