At my last job, there was a single occupant disabled restroom in the rear foyer of the building, feet away from where I parked. Could not have asked for a better location. Private, discrete, and close to my truck.
I haven't been at my current job for long but have recently asked for accommodating space (a private single occupant restroom with a garbage can) on property. They are going to provide a space for me that isn't the general restroom with stalls. I'll have to walk a little further but that's actually good, I don't want to be in the same building I work in, with my diaper bag.
I don't have enough room in a the standard disabled stall to clean up and change, and I've had to go off site for this most recently. I didn't like having the call but I think I'll be happy with the results and having a safe space at work to take care of myself.
Edit - I work from home mostly so changes aren't any problem whatsoever. Being on site is tough but should be getting better soon.