Although I don’t live in the Peaks, I’ve ridden lots of fairly steep and plenty of long climbs on my single ringed bike now. And to be honest, it just forces the issue of the climb a bit more, and you get out the saddle a bit earlier like you would on a singlespeed, but you’ve still got low enough gears to climb anything on it.
A 1:1 bottom ratio “should” really be low enough for most reasonably fit and strong mountain bikers (I’d not recommend Single Ring to beginners or people lacking in some base fitness tbh), and in practice it usually is… For about the first 2-3 hours of a ride. After that I always found I was longing for a slightly lower gear just to help a bit when I was tired, so swapped the 36T ring I had back out for a 32T again. So it’s 32Tup front, 11-36 out back for me.
With a 2.25″ Maxxis Crossmark out back, the only time I’ve ever spun out was on a long downhill stretch on road. Offroad, I don’t think I’ve used the 11T cog more than once or twice, and only get down to the 13T occasionally. On road, on the flat it’s usually sat in the 13T cog and I can spin along at a nice pace. So I don’t really long for any taller gears to be honest.