Option 2:

Still starting in Boulder, up through Estes Park and Rocky Mtn, but out of Rocky Mtn cut south sooner go through Winter Park on US-40 to I-70 back into Denver.

Works out to be 185 Mile at about 4 hours 20 Mins.

I uploaded both routes with map sections (rough) in word if you want take a look. I'm open to other suggestions...