Can one have both sleep apneas & narcolepsy?

Sure: In narcolepsy, you just skip all the early phases of sleep, and just go to sleep immediately and at inappropriate times and places. Once alseep, you are not immune to the potential of blockage of the airway and apneas that everyone else has. So you can be narcoleptic, and experience apnea once you are asleep.

Extremely unlikely: Having sleep apnea makes it very difficult to establish the diagnosis of narcolepsy.

Yes: Yes you can. These are not mutually exclusive diseases.