Big Daddy and I live in the French Concession and often discuss this. He has had knee surgery and I had ankle surgery. We are fine but once in a while an elevator would be helpful. We have noted all over China how there appears to be no "handicap" ramps, sidewalks cutouts, handrails, and many times there are obstacles. And all the uneven and not leveled granite and marble can be quite slippery. Even in the better hotels I have not seen assist rails or handles in the bathrooms. Although our hotel/apartment did put up slippery when wet signs.

And the "for weak only" bathrooms stalls are not assist equipped nor wide enough for a wheelchair in the ones I have seen, even at Pudong airport.

Even our doctor at the Ritz Carleton 'Portamon' Center is one level up and you must use stairs???

That said, Xintiandi is a wonderful area that would be not bad for a wheelchair if you are stressed at some of the other areas. There is a blog on FB, I think it is Sara's China Travel or just try China Travel with some good hints and I think she may take questions for contacts. I think she has been here 7 years and lives in Shanghai.

One thing I can say, for the most part in the service industry the Chinese are pretty responsive to helping people and very kind. If I get any good information I will follow up with you and I hope you have a great time.