Yes, you must be persistant and flexible to consume OP miles. Their "limited availability" is very limited . Ask lots of questions. Propose lots of options. Ask about partner airlines. Be willing to take the 6 AM flight or the last flight out.

After searching CO Online, I spent 90 minutes on the phone with CO today, and did come away with a reservation without reverting to sleazypass miles . Granted, January is not a prime time to go to Europe:

EWR-LGW
LON (LHR)-SNN [via EWR what a hoot]
DUB-EWR
Europe, open jaw, with stopover reward for 50,000 miles. The laugh is the LON-Ireland leg via EWR. Mileage runners' dream! CO partner KLM doesn't fly into SNN.

I'm going revenue (work + MR ), GF on miles.

Similarly, last Sept. GF flew:
EWR-BRS
LHR-LYS on Air France
MRS-AF-CDG-CO-EWR
Same Europe open jaw with stopover reward for 50,000 miles

Rewards can be had, but only with persistence!