According to Sheldon Browns Gear Calculator:
Sheldon Brown's Bicycle Gear Calculator
I'm running my Rohloff at approx 16.2 to 85.2gi, with 622 rims and a crank ring of 34.
When my 16T chain ring wears out, I'll be replacing it with a 17T which will lower me down to 15.3 to 80.2.
Thats if I can wait that long as I struggle on some of the hills locally when I'm loaded up.
This is still within warranty spec for an under 100kg rider with a max low ratio of 1.9 which is equivalent to
32:17, 30:16, 28:15 and 26:13 teeth
Sprocket ratios: www.rohloff.de
I like to keep my cadence in the low 90's rpm wise where possible.
I'm happy to coast down hills but prefer to ride up them rather than walk if I'm able.
I'm not a strong rider and my knees are starting to demonstrate the years of abuse I've offered them.
I'm looking forward to adding that extra tooth at the rear.
I never use the top couple of gears in my hub.
I think you'll enjoy the 15 gear inches and will have no difficulty remaining upright if you can spin in the high 80's rpm for the duration of any hill..
My bike is a steel framed 29er Mountain bike of I think 16kg without the panniers.
Maybe a little lighter without the Berthoud fenders which I've just taken off in anticipation of some off road touring.