We used Tiffany in November....they made an automatic stop for us at a Publix. We didn't request a specific grocery store, they picked for us. We had 20 min to do our shopping - plenty of time for me to get milk, bread, eggs, and some other things I couldn't ship down. If you have enough time, you can ship yourself a care package. I shipped cereal, snacks, coffee, tea, extra film and batteries I didn't feel like carrying. Call the front desk of your hotel for the address.
BTW, we really liked Tiffany. There were 10 of us - 4 adults and 6 kids. Two of the kids needed car seats. They went out and bought a booster seat just for my son - we took it out of the box and put the cover on it for the driver (he was fumbling with it, and I've got 4 kids - could do carseats in my sleep!). We were an hour late getting in via Amtrak, and they were there waiting for us. We gave them the return time to pick us up for the trip home, and there they were, waiting for us. Wonderful service. Also, if you check out their website, there's a $5 coupon to print out.