Hi Laura,
Thanks so much for visiting the Disney Parks Moms Panel with your question. I have a few ideas that might help to make your vacation a little smoother, even without the extra pair of hands.
When you are in the theme parks, be sure to take advantage of the
Baby Care Centers. The Baby Care Centers have quiet places to change and feed your little one, as well as to just take a break from the theme park. They also sell items such as diapers and wipes in case you forgot them at home.
Since you have a 7-year-old and a 1-year-old, my guess is that they are on different daily schedules. Especially in the mid-afternoon when the little one might need a nap, I would suggest that one adult go back to the resort to let the little one rest, while the other stays out with the 7-year-old. This should help to keep the children happy, and by extension, the parents! Then you can come back together later in the afternoon. Even though we only have one child, my husband and I would do this when she was little. One of us would take her back to the room to take a nap while the other stayed out at the theme park.
A final idea for you is to look into hiring a Parent Helper. The Parent Helper could go into the theme parks with you and help you with your children. Although you might not want to do this for your entire trip, perhaps there are certain days on which you feel like you could use an extra hand. The company that can provide a Parent Helper is Kid's Nite Out. Their website is kidsniteout.com, and their phone number is 1-800-696-8105 or (407) 828-0920. You can also e-mail them at officecontact@kidsniteout.com. There is an hourly fee for this service, plus you need to pay a transportation charge and theme park admission for the Parent Helper.
I hope this gives you some ideas, Laura! Please do not hesitate to ask if you have any further questions.