WooHoo! Good luck! Hoping everything is uneventful.
You do have plenty of high carb food, right? Most people with Big Gulpers (high dose kitties) keep several cans of high carb gravy food on stock along with karo syrup (honey or maple syrup works fine too.) I never needed to use more than a low-dose cat with punkin - his blood sugar would rise with a teaspoon of gravy, but I've heard stories of people needing more than that for the high dose cats. One tip - you can increase the carbs of any cat food by adding the sugar syrup to it.