I don't think your situation is so much an 'either/or' thing as it is a combination of things.
I was early onset menopause beginning when I was 43. Lucky for me that was right around the same time I went 'bonkers' and was diagnosed with PTSD.
Insomnia became my constant companion, which I attributed more to the menopause than the PTSD though there were times when my PTSD would not allow me to 'turn my brain off' long enough to get to sleep. I barely functioned during that time. The good news is, it does get better. I literally and figuratively 'sweated' out the whole menopause ordeal because I didn't want to take hormones - real, artificial, or natural. I'm glad now I made that decision because in the long run it has paid off.
As to benzodiazepams, I have tried Ativan, Xanax, and am currently taking Klonopin. The Ativan really messed with my short term memory, so I stopped after a few months. I took Xanax only on an as needed basis when I first began EMDR because it made me too sleepy. I now take Klonopin 1 mg twice a day. I started at .25 mg a day and have slowly over the last year worked up to the 1mg dose. It works great for my anxiety and if I am having trouble sleeping i.e. ' I can't turn my brain off to save my ever-lovin' life' syndrome, I wait and take the second dose closer to bedtime.
I say do whatever works, and if taking the Xanax at bedtime helps, stay with it. If at some point it doesn't work anymore, try switching to Klonopin and see if that helps.
Unfortunately this stuff is a lot of trial and error because what works for one person, doesn't work for another. It sucks, I know, but well worth the effort when you finally find the combination that works for you. I have a concern myself about the length of time I have been taking Klonopin, and at my next pdoc appt. I intend to discuss it with him to see if it's time to switch to something else.