Candy Apple Syrup Leftovers or ??/
If you try to use a dry method (don't add water to the syrup when you heat it back up), you will likely get a very uneven heating and risk ruining the syrup. If you use a wet method (add water and let it evaporate), you will spend as much effort and time on the coating day as on making it from scratch, so your preparation would be superfluous. 

So, while in principle it could be made to work, it is easier and quicker to not do it. Just do it the normal way.