mhh.. i just tried to do that and found that using free transfrom is not that good an idea as i thought.. it resaples the edges in the original picture and by doing that changes the colot at the edges.. don't know how that'll effect the game but better not take a risk ;)

instead you could open the regions file seperately and resize it before you pase it into a new layer. make sure you use nearest neighbour as the resampling option to avoid the effect that happened above..
(there might be an some place where you can change the resampling options for the free transform tool, too; i just don't know where)

ps: sorry for triple-posting still don't know how to edit