I've thought about ordering one of the "filli's" this year; they should survive, as they were bred in Nebraska by the same (late) brothers who hybridized all the hardy hibiscus. Years ago I kept one of the Hopi crapes going for a few years in Cedar Falls, but it would die back to the ground each year, so would be a foot tall each year. That's the deal with the filli's; they state that in colder zones they die back to the ground and resprout, and even in warmer zones only grow to 18 inches... so you're not going to have a crape myrtle tree, like in the south (they call these dwarfs myrtlettes). It would be worth trying if you're happy with a foot tall crape myrtle.
don

I ordered 10 from somewhere (new england maybe?) and only 1 survived (they were like twigs when I got them) The lone survivor last year was 4 foot tall by the end of the season. It does die back every year. Where did you find yours? I would love to have some more as long as they don't come as twigs!

I found my crapemyrtle at TimberPine Nursery (15 min west of Des Moines) They had two colors the red and the coral but limited numbers for right now. They were 5 and 7 gal containers and nice.

Lowes has a ton of them- reddish, bright pink, and purple $15