Well, I am probably not going to answer you question, but I will offer an alternative.
I stayed at OKW in June 2005 and called a cab. It arrived in 10 minutes, took me to a grocery store. Dropped me off, and I called the same cab line when I was in line checking out. The cab came so fast, I hadn't made it through the line yet. I called again to be informed they had come and gone.
They sent another cab, and in 5 minutes I was on my way.
For us, the cab ride and fare was way cheaper than the delivery services, and it was really quite efficient.
I bet you can call a cab, be in and out and back in an hour or so.
So while others are unpacking, you can go run for the snacks, drinks, or whatever you need.
Also check in time is 4pm at many places, so if arriving before then, that would be a perfect time to make a run. If you have cell phones, you can meet up with your family shortly thereafter.
Sorry, I didn't directly answer your question. I just told you what I did and offer it as an option. Ofcourse it all depends on your arrival time and your situation.
Have fun!
-Mark