No. They would not be able to tolerate the winters.

I think even Zone 6 is pushing it -- but there are several (all with American Indian names) developed by the National Arboreteum here in Washington DC when we had colder winters that survive in 6.
My Dynamite is just now pushing leaf growth and I'm 99 percent sure that the late freeze killed off about 12" of every branch. Haven't trimmed it yet, but will probably have to; else it'll look bad.
I'm really sorry for you, 'cause I think crepe myrtles are TOPS.

Even if they did "survive" they wouldn't bloom well which is one of the key selling points.

These can be perennials in zone 5:

CHERRY DAZZLEÂ DWARF CRAPE MYRTLE
Lagerstroemia 'GAMAD I' - PPAF

SARAH'S FAVORITE WHITE CRAPE MYRTLE
Lagerstroemia x fauriei 'Sarah's Favorite'

SNOW DAZZLEÂ MINI CRAPE MYRTLE
Lagerstroemia 'GAMAD III' - P.P.A.F.

TOWNHOUSE WHITE CRAPE [crepe] MYRTLE
Lagerstroemia x fauriei 'Townhouse'

Here is a link that might be useful: link

Darn!

Oh c'mon like you can't plant a million other things there in that zone that can't be planted in Virginia?

I would think your best option would be one of the smaller ones, kept in a pot, and moved to an unheated, sheltered building - garage, barn, etc., even your basement - for the winter. That MIGHT give the needed protection for the winter cold. I dunno about the cooler summer nights though...

treeguy123 what kind of regrowth and how much bloom could
quirkyquercus expect if she tried to grown them as perenniel (I'm assuming they'd die back and put up new growth each year)

Every gardener in the world craves something that she can't grow, but the best advice is "Bloom where you're planted."

BTW, can you grow Rose of Sharons? I have seen them pruned up like crepe myrtles, and very handsome they are indeed. The best varieties are the sterile ones, like 'Diana' so you don't have a blue million seedlings to deal with, though 'Bluebird' is a stunner and not sterile.

By golly, you're right laceyvail! I grew both diana and bluebird rose of sharon's in VA and completely forgot about them, because I moved away before the tree's were very big. But YES! They are hardy enough to grow in MT because I've seen them in the city. Thanks.

I live in Chicago and have a crepe myrtle standard (variety Sioux I beleive) that I have been growing in a 16' clay pot on my patio in the summer and keep in my unheated garage in the dark during the winter where it doesn't freeze but stays about 40 degrees. I have had it for about 10 years and it has even develped exfoliating bark. I just fertilize it in the spring and it releafs out every year and blooms heavily for me in the summer. I leave it out until a frost knocks the leaves off and return it to the dark garage, only watering it when it is completely dry. I also have a couple outside against the south side of my house which I treat like tea roses. I mulch heavily in the fall and they freeze to the ground everywinter but grow about 3 foot high and bloom for me in late summer. They are varieties Velmas Royal Delight and Centennial. They even survied this past winter when it was below freezing for 5 weeks straight and are now about 6 inches tall and growing.

I bought 10 crepe myrtles from a company out of New England (I believe)I am in Iowa, bordering zone 4-5. Only 1 survived (they were twigs when i got them so that could be why)
anyway, they are basically perennials. After the first overwintering, the sole survivor came up but did not bloom. It only got about a foot and a half tall and than it died off. The next year it came back and got about 3 foot tall and did have some flowers to it. Last year it was over 4 foot tall and loaded with flowers. I can't wait to see what it does this year. Not a tree- but a reminder at least :)