London doesn't mention much in the way of services either. I have moderately high hopes- because I think they are using facilites built for the Olympics (and Paralymics) but that's no guarantee.
https://www.loncon3.org/

Looking further out to Spokane Vs. Orlando (which will be voted on next summer),
One of the prime selling point of the Orlando site is accessibility (golf cart shuttles around an enclosed ground), they already have been thinking about fans with disabilities.
(Spokane looks pretty cool too, but I can see how "its all so walkable" raises red flags for people who have concerns about either mobility and wayfinding.

http://www.spokanein2015.org/wordpress/
http://www.orlandoin2015.org/