Unless you just don't want a crape myrtle in that spot, there's no reason to move it. It will grow back so fast you won't believe it. I would let it grow for a year or two and then begin pruning out the stems you don't want and limbing up the ones you do. In 3 to 5 years, it will be full grown again.

If you want to move it, I would wait until fall to do so. The ground will have more moisture in it and the tree will have cooler temps in which to establish a root system before summer rolls around next year. Even if you move it, don't be surprised if more stems come up from the roots you leave next spring.

We lost one of our crape myrtles during Gustav last year. This year it's put out shoots everywhere. I'm letting the ones in the general vicinity of the old tree grow back. They're about 4 feet tall now and blooming. Pretty amazing, I think.