So the question was about the Death Ride in the Sierra coming up next weekend.
https://deathride.com/course/
It's 129 miles and 15,000 ft climbing. The main problem with the profile is that you either going downhill or climbing a HUGE mountain.
I did numerous centuries with a lot of climbing and I don't have a particular plan for them. I hit them hard from the beginning and sometimes I finish them with no problem, sometimes I have a hard time at the end but slowing down helps to finish them fine. I didn't even had a HRM until last month.
For the death ride, I know that I can't hit it hard. I know that I have to pace myself and since I have a HRM, I can use it.