Certainly a lot of the roads are steep which needs a low gear to get up. I'm not going to pedal down those hills as I'll be too busy with the brake levers :-) There's quite a few long level/gently sloping roads in the valleys or on the top of the Cotswolds where a high gear might increase my maximum speed. Don't think I care :-)If I lived in Stroud, where most roads in the vicinity are either massively slow or massively fast, there's no way I'd consider restricting myself to just one chainring, except at gunpoint.
With the current 2x5 setup I have 8 usable distinct gears from 36-91". I occasionally wish I had an extra high gear so my proposed 1x11 setup gives me a top of around 100". I definitely need an extra couple of gears at the bottom and plan on 33, 28 and 24". Sometimes, on the few flat roads around here, I am slightly irritated by not being able to find exactly the right mid-range gear. I have one gap that is 17% but on the proposed 1x11, it's 13%
A crazy idea occurs to me - have a wide 11 speed cassette and two chainrings with about 6% difference. Most of the time, I would ignore the front derailleur - just use it for fine tuning when I really wanted a gear in between