I just finished my 1st attempt at racing the Tour Divide, about 1000 miles in 7 days.

my tool kit was/is
Park Chain tool
extra quick link
hand pump
1 tube
patch kit
allen wrenches (only the ones that I actually need)
1 small swiss army knife (the smallest one they make)

I use stan's latex sealant to convert a set of WTB Vulpines to tubeless
when/if there is a puncture, it simply self seals

other tours if done, are not nearly as remote as the Tour Divide route.
its really easy to simply reduce

however...
last year, touring Portland to Ventura, I met a guy carrying a floor pump!