Do you know whether your flight from Chicago to Miami is originating in Chicago? I would have to assume that it is, since you are getting there to Miami around 9 AM. But, you know what happens if you assume!! If your flight is originating in Chicago, you should be OK, as your flight should arrive on time in Miami. Delays in Miami usually occur much more often in the afternoon, because of thunderstorms. Don't know about delays in Chicago, but at least in October, you shouldn't need to worry about snow and ice!!
As far as Miami itself, they have MOST of the Skytrain back in service now, and perhaps it will all be in order by October. As far as cart service in Miami, as far as I know, that is very hit and miss. I do not think you can set that up ahead of time, like you can for wheelchair service. You can always request wheelchair service. Who knows by October what the arrival situation will be in SXM. IF they are still in the temporary arrivals hall, as you know, I guess, it is currently a clusterf*ck. Depends on the day, but can be a total trainwreck. So wheelchair service would be helpful in SXM at that point.
All of that said, did you ask to change to a different flight?? As of now, there are two flights per day to SXM from Miami. Don't know about October. If you see other flights that make you happier, call back!! Often you can get a different answer if you call back again. Best wishes!
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