I’ve got a fair amount of experience with ASE. I go there every couple months in my ‘C. It’s a beautiful trip.
My parameters:
1) Severe clear. I have the luxury of living in the front-range and can pick/choose which days to go. I realize coming from elsewhere you may not have this flexibility so, I would say 8NM vis minimum. Safety aside, it’s such a pretty trip, why waste it on a hazy day?
2) Light winds aloft en route. My max is 30kts at mountain tops. Look at both the 12K and 15K charts. If either depict winds above 30kts I would stay on the ground. If this is your first time