Tips for a large quick gumbo?

[Salty nurse]

So I've been asked to cook a large gumbo for a fundraiser in late October and I have a couple of questions. Have any of you ever precooked a large roux and added the veggies the night before? There is a time constraint issue so that's why I'm thinking of making that mixture the night before. I thinking of doing that and making a chicken bone stock the night before and letting both the stock and roux/veggies come to room temp then adding them to my pot with browned chicken and sausage. Any suggestions would be greatly appreciated, thanks!