There are two different species of Wax Myrtle (Northern Wax Myrtle and Southern Wax Myrtle). The Northern is semi-evergreen to deciduous; Southern one is deciduous. Northern one would probably is a better choice for you. Regarding the Crape Myrtles, many are fine to zone 6b/7a. Most all of mine survived...even after the Winter from he// (deep snow probably helped with that btw). The thing is, you need to consider heat requirements (as well as cold minimums). If a zone does not experience enough Summer heat, the wood may not properly ripen. So ironically, there are many semi-tropicals that will grow robustly in the Mid-Atlantic zone 7ish climates that do less well in Pacific NW (Zone 8+ climates). Crapes have a relatively high, Summer heat requirement. It's July, see any in bloom around you. Finally, you specifically wanted a 'tree'. Crape may be a viable option for you as a shrub (with some degree if annual dieback), but not sure if a tree is possible. Give it a try and good luck!

Anyone else get into a Crape Myrtle obsession? I started collecting them a decade ago..., Zuni (magenta), Hopi, Dynamite, Catalba (purple), Tuscarora (coral/pink)...This week, needed to cut out all but the Hopi. People do not realize that many eventually want to be TREES. My favortes are the pure indica Red Dynamites and the Hopi (it's hybrid with soothing pale pink colors). I just ordered another Dynamite for the two I had removed, but different location. Above is Dynamite Red The Hopi is the one above the right with the paler soft pink colors, and I prefer it to the more garish Toscarora.

Chas045 wasn't belittling you at all. He meant "it might be a draw" to prune it like that because crape myrtles bloom on new wood only. It will grow bigger branches for you and bloom better this summer. That is why alot of people and landscapers cut the crape myrtle back like that. Don't worry about it, it will be fine. You won't even notice it in a couple years, they grow really fast. It will bloom better for you, wait and see. Smile and be happy.

the base problem.. is that .. as a babe.. it was planted for the size of the plant at point of sale ... with no real concept of its future potential ... once it stated growing.. 1 or 2 feet from the foundation .. there was no choice as to pruning ... but crape murder ... its simply to big a plant.. for where it is planted ... sometimes its easier to cut bait ... and start over ... and either plant it a bit further away ... OR ... buy a plant with smaller potential ... OR ... properly prune it every other year or two ... on the other hand ... [its never simple... lol] ... and do understand i have never had a CM up here in MI ... so i will defer if i am way off base ... you might try hardcore renovation ... go in there and remove the largest 1/3 of the trunks ... trying to get it to resprout way down low ... next year ... take the second third ... etc ... inside 3 years .. you will have refreshed the whole plant.. to new vital growth .. which you can train properly over the years .. [until you move and leave this nightmare for the next peep .. lol] .. upside here .. you learn a lot about pruning ... downside ... its right in front of the house .. perhaps not the best place for such an experiment ... https://duckduckgo.com/?q=renovation+pruning+of+crape+&t=ffcm&ia=web when i bought my first house.. there was a slew of 40 year plus shrubs... and i wanted to save them .. for the history of the house ... 5 years later i removed the last nightmare ... one of the happiest garden days in that garden ... pshaw on house history .... after all.. i didnt keep the paisley 3 inch shag rugs either.. lol ... https://flashbak.com/selling-harvest-gold-shag-carpet-ads-from-the-1960s-1970s-385094/ play around.. learn to prune.. but keep it in mind.. that removal might be the best answer ... of course.. if you are an instant gratification type.. just do it now ... ken