Hey! I am not sure where you read about not bringing adult beverages on Disney property. I have been trying to find if there is a rule about that and cannot find one.
I did come up with a couple of other options for you:
1. I have read that if you call Garden Grocer directly, they may be able to add beer to your order, so that may be worth a shot.
2. You could take a bus to Downtown Disney and walk to the Hess station to purchase your beer, but that may be a long distance to walk with a heavy package. Alternatively, that would be a quick drive for a taxi if you wanted to try that.
3. I have gotten conflicting reports from different resort gift shops about whether they sell beer only by the bottle/can or as a pack. Some have said that they do sell six-packs, while others do not, so you will want to check with your resorts gift shop before you travel. You can probably just call your resort's number and inquire about it.
4. Another option that was recommended by fellow mom's panelist,
Joel, is to use the site WeGoShop.com. They have a wide variety of options and also deliver. You can check out the above link on his name for his full answer.
Let me know if you have any questions about this!