|We have a lot of patients with your same situation.
It is fine to mix shakes ahead of time. They will need to be refrigerated until you drink them, or you can make them up ahead of time and freeze them.
You then can leave them out to thaw and drink them when you are ready. If it is too frozen to drink when you want it, you can put it in the microwave for about 20-30 seconds at a time.
I have many patients that will make and freeze several at a time.
I hope that this is helpful.