We are not using an infant carrier in Disney since it will be way too hot to keep her in it plus we don't want to carry it on and off the buses. We will use our stroller in the restaurants that don't have the infant high chairs. This is what we did for DS when he was too young for a high chair, and the CM's were great about allowing the stroller inside. Unless we are feeding her, we don't generally hold her while we are eating in restaurants. Have a great trip!

Otherwise, we always just held babies too small to sit in a high chair. I remember at Chef Mickey's that they have seats that look like infant carseats on wheels that they brought to our table when our oldest was 4 months.