Up here in this part of buffalo country the professionals like doctors, pharmacists and even the kids of the wealthy who have degrees from English speaking universities (but are now just salesmen in their parents' stores) have basic, but limited, English skills. But it must be difficult for them as they do not use it on a daily basis and as others have said it is easy to forget a second language if not using it.
As for expats that speak/understand Thai it is much easier for them as it there for the most part of every day.