I ordered a box from
Amazon Prime Pantry last year and it was kind of a hassle to get it. (we also stayed at ASSp) The front desk manager said that when a box arrives prior to you actually checking in it goes to central distribution (I think that's what he called it) where it sits until you check in. They will not hold the box at the hotel until you arrive. After you have checked in, it is then put back out for delivery. After spending a lot of time at the front desk and bell desk, my boxes were finally delivered around 1 am.
My friend had the same experience. She ordered a case of water from Costco and they did not receive it until 2 days after they checked in.
I would recommend using one of the local grocery delivery services. I'm not sure why it is treated differently but whenever I've ordered groceries (I've only used Garden Grocer but many also like We Go Shop) my order is waiting for me and ready to be delivered to my room within 30 minutes.
If you have the option to fly Southwest that may be your best option. You can check two bags per person for free so you can bring whatever you need.
Good luck!