The problem you have besides the obvious one is that the owners will of course if they can, get you into a bottom floor room but they will not leave a room empty for a few days to do this as they have to fill back to back to maximise on the income
The ones on the lower floor do have a lower terrace but there is a drop down onto this so even abled bodied would feel this.
It does not matter if you get the lower or forst floor as you still have to climb exactly the same amount of steps
I would say 8 up into the building and then you either go down the same amount meaning that you then have to climb back up that or you climb up to the first floor meaning you have the same amount down again.
So there is really no way around it, lower floor or first floor it is all the same.
The only other way around things and to be sure is to actually move apartments and go somewhere with an elevator and then you are certain about the mobility side of things