Castle Rock to Colorado Springs?

Needing to make the trip by bike in September and reversing in early October. Searching the archives, the google-recommended route of 83 is a resounding no, leaving as maybes 105 and I-25 and its frontage road. But none of my search results were written within the last 5 years. Around my parts, 5 years can make a huge difference....so, dear bikeforums is 105 doable these days or should we stick to the I-25 corridor?

If it matters to your recommendations we're flatlanders, but year round, northern climate bike commuters who have ridden interstate thru Arizona so I-25 doesn't scare us conceptually.

Thanks in advance for any inputs.