Talk to your othopedic about the distance you might be using this, just a week out of no weight. If your just starting to put weight, i doubt you would strong enough to do this for miles and miles 8-10 miles. a day.
I've seen someone with what looked like a walker with wheels, but had a seat like place to take a break. Well, when i saw the person. It was being used like a wheelchair, someone was pushing "mom" around. I suspect to much walking had wore them out.
If you decide to use your device, make sure to bring a couple numbers of the offsite wheelchair, or
ecv rentals. This way, if you figure out that first day, its way to much for you. Rent a wheel chair in park, and call the offsite rentals to get something delivered the next day. Be careful that first day, you don't want to go overboard, re-injure, and cause yourself a weeks worth of pain, making disney less magical. Don't forget your pain meds if your on them, bring thm in the park. It may be fine in the morning but 4 hours later could be something else. Its a long trek back to the room even staying on site.
Best of luck.