Idle Speed?

During these colder months, I need a good 3-4 minutes of "foot throttle" just after starting to keep her from stalling. Once warm, my idle is about 700 in park & 600 in gear. I never thought of the oxygenated gas mentioned above. . . but who knows. By the time I get around to adjusting for this, it'll be springtime & I'll have to reset it back!
~ Joe