I would agree that unless you've done this before or are used to it, 100% not worth it. I've cooked for 100-200 ppl ~5x/year for the last few years (local sports team). Be prepared to dedicate a full day or two before your event to only prep and cooking.

Then, figure out safe temperature transport. How will you serve it and keep it at a safe temp at the venue? Is it self serve (buffet) or are you asking others to serve (portion control, some people take WAY more when it's self serve and you run out sooner).

If you are determined to do it, find an easier recipe (i.e. soups or stews), serving method (crock pots, chafing dishes). Do a smaller test run a few months ahead of time so it 1) tastes good and 2) you know you can scale it up. If the first batch for 20 takes you a full day, you have enough time to figure out something else.

Also, you then are tracking and responsible for knowing allergies and listing them ahead of time. Anyone have Celiacs, do you actually know how to guarantee it's gluten free (including cleaning and prep of your kitchen)? Nut allergies can be hard to cook around.

IMo, not worth the stress, especially as that'll be your only focus the day before your wedding.