Every morning, but I wake up wrapped around a beautiful naked woman every morning too so that's not surprising.
I wouldn't be too worried if you don't get it every morning so long as you're getting hard throughout the night otherwise. You'll naturally get 4-5 erections every night while you sleep, but the morning wood part is just the one that you're in the middle of when you wake up, or one you get while waking up. If you're getting up with an alarm clock in the morning, and wanking a lot during the day, it's not too surprising if you don't have it.
When I travel somewhere where I get jetlag, I don't get the MW since my body's sense of timing is all mixed up. Try just not JOing so much and make sure you get your sleep schedule under control