I probably averaged 150-200 miles / week in the weeks leading up to it.
I’m carrying too much weight and knew I would suffer. The toughest climb - 16 miles from Aspen to Independence Pass, with a 4,000 ft elevation gain to 12,000 ft - about ended me. The climb took 3.5 hrs, including breaks. Got to the summit and still had over 60 miles to go for the day. No way. I rode the support wagon for the final 25 miles.
Did not expect to do the full route but hoped to do all the climbs, so I’m thrilled with how it went.