Hi, I live in Cincy as well and interned at the Zoo, where there are many great crape myrtles. It is important to be careful to select varieties that are quite hardy (ie: Hopi, Zuni, Natchez, etc.) Also, siting is most important to determining whether you have a woodier specimen. I always tell customers not to plan on crape myrtles as focal point trees necessarily, as some hard winters can kill them down to the ground like butterfly bushes and Caryopteris. However, crape myrtles near buildings, especially those with southern sunny exposures, have higher probability of retaining more bulk through winter. We have some great myrtles at the zoo and at Spring Grove Cemetery that prosper merely by being sheltered near groves of trees and other elements that allow them plenty of light while also diminishing winter winds. More exposed plantings can run the risk of dieback, but even then established specimens can send out massive regrowth each season, similiar to butterfly bushes. Also, always remember that crape myrtles are very late to emerge in spring, so don't give up prematurely on them ( many customers dig up healthy beautiful plants in May because they think they are dead, when the plants are merely dormant!)
Lastly, I don't know if this would affect too much, but remember our heavier clay soils can stay colder later into the season than other soils, so perhaps work your desired area with compost and pine soil conditioners so as to lighten it and allow earlier season regrowth on a plant that is traditionally very late to leaf out in zone 6.
Good luck.

We've had an Acoma Crapemyrtle for 4 years now. It has done well except for last winter when we had that late frost. The branches all ended up dying but the roots were fine. We cut off all the branches and it started growing again last year and continues to do well this year. We have since learned to cover it if there is a warm up then frost. Now ours looks more like a bush, but we still really like it. Eventually I'll trim it to look more like a tree again.

i was just about to suggest that siting is the key to being successful with a crepe myrtle. it was driven in by force yesterday when i sighted a 2 story specimen in bloom growing here in akron, ohio. it was right up against a brick house on the direct south side. at 30 feet, i don't think it dies back to the ground every year. but wow did it
look great.

the zoo here in cleveland maintains many crepe myrtles
as does rockerfeller park(the park is right on the lake)
both places have them in sheltered sites. but neither place has large plants-- so i assume lots of die back.

you should also considerm some of the more cold hardy
selections.

diggerb