Thanks for being here

First of all, have the ladies bake smallish cookies or cut smallish bars, just 2-4 bites. Most people at cookie fests want to have a lot of different ones. The standard large bakery bar cuts 4 of the right size for this type event.
1- Bar cookies baked in large sheets are easy and VERY popular. The large 18x24 sheet cuts 72 2x3 inch squares. Brownies, scotchies, 7 layer bars, oatmeal bars with dates, raisins or other dried fruit, choc chip, many more. MUCH faster than drop cookies...
One sheet holds 4 times the recipe for a 9x13 pan.

All the recipes below can be made and frozen. Start now:

www.bhg.com/christmas/recipes/make-and-freeze-bar-cookies/

food52.com/blog/20990-freezer-friendly-cookies-bars-brownies

One baker with a food processor can do 100 large biscotti in an afternoon using my biscotti baking binge on this site. For your party, I would make more in a smaller size:

www.ellenskitchen.com/bigpots/biscotti.html

More adventurous bakers who want to do fancier cookies:

theviewfromgreatisland.com/30-best-freezable-cookies-recipes/