for example you mentioned Hump Mtn, just do a warmup and then pedal at roughly 75% which for you at +/- 5% gives you 70-80% at 190-217W. In my experience on flat&windy terrain, it is fairly straightforward to keep power roughly in 20W range by targeting 200W.
My main targets on bike computer for something like that:
- 10 sec power
- lap power
- power graph with 1-sec power and average power for entire ride
during the ride I’m glancing down occasionally and keeping all 3 at same level, mostly be feel. It took a week or two and then it was pretty easy to “feel” 65% (endurance) or 80% (lower tempo).