Actually I am using the Apple Maps app heavily during my travel time, and it is a good way for us to obtain the offline GPS maps ( but always the free and latest version) of any country.
For instance I am in Malaysia now, but I just keyed in one start point of USA address, i.e., Apple Cupertino, and I entered the end point of Tesco in Texas, then I can keep this as for offline usage.
So, I think you can apply the same rule either you are in Malaysia or overseas.
Or maybe our iPad Forum Readers can provide us more suggestion? ^^