I checked using ABetterRoutePlanner.com using their beta model for the LEAF Plus (62kWh battery). It says it cannot currently be done with CHAdeMO even with the longest range LEAF available. As WetEV said, you'd have to find Level 2 chargers and campgrounds and take a very, VERY long time to make the trip. The smaller batter LEAFs are not meant for road trips.
But if even the 2019 LEAF Plus can't make the trip, what BEVs can?
As a comparison, Google Maps says it would take 8 hours
in a gas car via the I80 route and 8 1/2 hours via the I70 route.
ABRP says you can do it in a Chevy Bolt thanks to the Electrify America network, making 3 CCS stops: https://abetterrouteplanner.com/?plan_u ... c27538172c
(but you are limited to 50 MPH in the long dangerous stretch using i70 where there are long parts with no services)
Nearly 15 hours.
The Hyundai Kona 64kWh looks like the Bolt: https://abetterrouteplanner.com/?plan_u ... 3d47c278f2
The Kia Niro 64kWH will make it, too, but it's limited to to 44MPH across Colorado (not sure why it does worse): https://abetterrouteplanner.com/?plan_u ... 4009b101ca
13 1/2 hours.
All of those go across i70 as that's where the CCS stations are, and the trip time is extended because of stretches where ABRP says to reduce your speed in order to reach the next charging stop. ABRP takes into account elevation changes. However, their performance data on all those cars is scant, so maybe those are wildly inaccurate figures.
With a Tesla you can choose either route, as there are currently SuC on both I70 and I80.
A Tesla Model 3 LR can do it in 9 hours
(only 1 hour longer than an ICE): https://abetterrouteplanner.com/?plan_u ... eb297f1cef
A Tesla Model S100D looks identical to the 3, also taking 9 hours
An S75D (like mine) doesn't fair as well, taking 10 hours
as charging takes longer with the 350V battery and it is maxed out at 62MPH for the first segment: https://abetterrouteplanner.com/?plan_u ... 76b2500bac