I've been mulling over a late-August/early-September ITT for a couple of years now. 2021 is probably also my next best time for a Divide ride, if the itch remains. The main potential drawback I can see to a late summer start is wildfire, fire-related road closures and smoke-filled air. 2018 was a terrible summer in that regard. This summer has been notably better so far, but as trends go, wildfire issues will probably worsen in the coming years.
Agreed, the risk of a late monsoon in Colorado and New Mexico is also a coin toss.
Last year David and I watched the weather during these dates and placed our progress daily, based on what we experienced and what we believe we could do in daily milage. We juxtaposed that to the weather and had a pretty clean run, weather wise.
Our plan is also to just show up and start together. We will obviously separate at some point.
I want no part of the daily snow pushes I experienced in 2014. To me, its worth the risk.