I wouldn't think you would have any trouble making it from Ft. Collins. 30-45 minutes to 470 and then another 20-25 to the parking lot. If the weather is bad or weekend rush hour you might just have to be around the house to head out if called. You could always jump over to 85 and go through Greeley if I-25 closed for some reason. I don't live up there but have done that drive many times. Good luck!