You're in a Cirrus-22 (and assuming IFR) with service ceiling of
17.5 and cruise of over 180 kts.

1) Have you ever done the Denver-LAS-SNA trip in another aircraft?
Something besides a B737, of course.

2) Have you flown a Cirrus more than 10 hours?

3) Have either of you flown the Denver-LAS-SNA route IFR before?

The highest MEAs on the direct Denver-LAS are 14.6. Are you
comfortable in a single-engine (altho high performance) with 2-2.5K
feet between you and the pointy tops of the mountains? That's
a question only you can answer.