No that's correct but...revs just doesn't sound as good so I'm nitpicking.
In my experience the gearing of a Diesel means plenty of power at lower RPM, but in petrol car shifting usually occurs higher. It all depends on how you drive, I can accelerate to 55MPH without going over 2K but it's boringly slow, normal acceleration results in shifting around 3K. Of course in my dads Honda it shifts even higher than that but it also doesn't redline until 7K as opposed to my 5K.
What does your car idle at in neutral? I'd say don't downshift unless you're nearing that point.
45MPH is like....really slow. You practically don't even need 5th gear at those speeds.