When I was on NPH I originally took it at breakfast and around dinnertime, but later moved the evening shot to bedtime. I didn't have any more severe lows once I moved NPH to bedtime (I still had morning lows, just not the needing-assistance-from-someone-or-calling-911 kind).
Once I switched from NPH to Lantus I suddenly "discovered" that I had quite a bad dawn phenomenon. Now that I'm on the pump it's not usually a problem, but on Lantus the only way to wake up below 200-300 mg/dl was to get up every night at 3:00 AM (when my BG was still normal) and take a few units of Humalog. If I ever went back on Lantus I would try something like taking a few units of NPH before bed to see if that helped without having too big of a risk of lows.
Have you tried Lantus or Levemir and using carbohydrate counting at all? Given all your problems with feeling variations in blood sugar, I'm kind of surprised you're taking NPH. I noticed a HUGE difference in how I felt on MDI compared to NPH; it even had a huge impact on my functional vision because the fluctuations in blood sugar cause my vision to go blurry if it's bouncing all over the place (I'm legally blind so even a "minor" fluctuation in my vision can make the difference between being able to read large print and not being able to).