This is actually the result of being pretty close with your choke pull-off adjustment, but just a tad lean, or the flap is open just a touch more than the engine can tolerate on a cold start-up.
On a good note, it's better than being a bit too rich, as this is not a good scenario for the engine. You might try adjusting the pull-off slightly by turning the adjustment screw clockwise every so slightly, which should help the situation.
It make take several cold start-ups to find the most ideal adjustment, and it may require just a bit less choke flap open angle for colder temperatures than what you are seeing now?......Cliff