There are so many places to ride in CA, the only reason to consider going all the way to CO is a change of scene.
My idea: Right now, Rte 1 through Big Sur is closed by a landslide again, out and back from either side would be amazing (though hardly flat). From Monterey it’s 45 miles to the roadblock. That’s probably a lot of climbing and you could start closer. If you were making a road trip of it you could do the aquarium the day after
SR 1
[IN THE CENTRAL CALIFORNIA AREA]
IS CLOSED FROM 4 MI NORTH OF LUCIA TO 14.4 MI SOUTH OF BIG SUR /AT LIME CREEK BRIDGE/ (MONTEREY CO) - DUE TO A SLIP-OUT - MOTORISTS ARE ADVISED TO USE AN ALTERNATE ROUTE