I know the usual size for a stable is 12 x 12, but what do you think would be the smallest size you could get away for overnight stabling? For a pony about 13hh for example?
I wouldnt go any smaller than 12 x 12 - in fact I think 12 x 12 is titchy as it is! However in Spain a lot of the stables are smaller than that and the horses cope - plus if is was a one off then some temporary stables are only 12 x 10
12'x10' would be fine, but if not a chunky type could probably manage in a 10'x10'. My 15.3hh Cob had to put up with a 12'x10' stable for 5 month (luckily in the summer, so only in during the day), till a bigger one became available and she coped fine. I just made sure she had a deep bed and big banks, so she didn't get cast, also fitter wall mounted feed manger and water buckets to maximise floor space (there is now a 16.3hh horse in there now
I personally don't like stables any smaller than 12 X 12 as i think that is small anyway, but you do have to put up with smaller ones such as 10 X 12 and this is fine if only for a night or two.