Take the monorail to Poly or GF and watch it on their beach. I know this a "no no" from some of the resort nazi's here on the DIS but when I stayed at the Poly, there were plenty of non-resort guests there relaxing on the beach waiting and it was fun. You can also take the monorail to MK and just not go in. Go back by the ferry stations and watch right there. Then hop on before max exidus
I agree with vacationwoman, there's a 4th floor observatory deck that you can go out and watch Wishes from. I saw plenty of people watching there. Then you can look right and watch the EWP from there too.