Hello jdaylett,
It is possible that we may not be able to get the miniature to you by October 21st. You will notice that on the product page for that item, it indicates that the item "Ships from our warehouse in 4 to 18 business days." This is the timeframe in which it takes the item to come from a supplier or other source before we can ship it to your address.
Once we have the item in our warehouse, we then ship it out to you, which will have the standard transit time based on the shipping method you chose. In your case this is 3-10 business days.
It's possible that the miniature could not even come into our warehouse until the 24th, and if we shipped it out to you that exact day, it may not arrive until November 7th. This would be the absolute long-end of the estimate, but I cannot guarantee it will arrive before October 21st.
With this new information, I fully understand if you would like to cancel or modify your order. Please just let me know if you require any assistance. Thank you!