The first person you should pose these questions to is your Doctor. They know what your leg can and can’t handle.
My concern would be, based on your saying it is a “possible stress fracture,” you are in the beginning stages of addressing your injury. Thus putting any undue prolonged pressure on your foot could make it worse. I dislocated and fractured a bone in my ankle requiring surgery. However I could not get the surgery right away due to another medical complication and my surgeon was worried about the injury possibly worsening and also it healing incorrectly on its own. So definitely find out what your Doctor thinks about you going and the best way to be safe.
I also will be going to DW possibly in a boot in 3 weeks. Many have posted what you can and can not handle in a boot but I believe it depends on where you are in the recovery process. I started in a boot, then surgery, then temporary surgical cast, then cast, then boot then a brace. When I told my Dr. about DW he recommended the boot to be on the safe side. I personally prefer the boot because I know my ankle will be safe. I walked all over manhattan in mine and it did not bother me at all. But somebody else may have a great deal of pain.
Don’t forget compression socks and bring ziplock bags to the hotel so that you can make ice packs. Also, ask for extra pillows to prop your leg up when back from the parks and icing your ankle. Another tip would be to spray your boot with deodorant to help with the sweat. And if you can afford an EVC definitely splurge.
Good luck.