Make sure to change the max.Scaling value in the ObjectEditor/doodads/yourdoodad to a high value (3.00 for example) and the min. scaling value to a very small value (0.20). This grants you the possibilite to stretch the doodad of your choose in many ways and better dimensions than the standard range from 80 - 120. Scale them the way geries suggested!
But be careful... tooo stretched doodads tend to look ugly, so it needs a bit of a good feeling to do it perfectly. But no question, some experience with it, will easily grant you the result you are aiming for!