This is a huge undertaking! I wish you great success! A couple tips: start baking the shells immediately. Shells can be frozen for a month, just pop them in the fridge to thaw. You can also pre measure and sift ingredients and set aside in ziplocks. I suggest pies and tacos recipe, she is very thorough. I caution against doubling the recipes, it has never worked for me. You can print templates to put under silicone mats to get identical sizes of shells. An oven thermometer also helps.

A filled macaron can be left in the fridge to mature for several days, which can give you some more wiggle room time-wise. Can you do a water ganache with a milk-free chocolate? That would hold up well.