The descent off sounds equally horrible. I remember coming down Mt. Lemmon and thinking, this really sucks. I just want to get off the bike and riding downhill requires a bit of concentrations too so it's not like you can zone out and go to your happy place. Can't imagine what this climb and descent would be like.
I'd go with the 32 cassette. Why not? Better to have the gear and not use it than to wish for one more during a super long climb like that and not have it.
Depends on who are riding for really. Do you want to be reasonably comfortable or do you want to impress luddites with their "any thing smaller than an 12/23 are *******" attitude?
Go with the 11/32 and enjoy!