I start the car and wait for the idle to stabilize then drive off. By stabilize, I mean that it is running smoothly, even if the idle is still high. I have done this all of my driving lifem even when I lived in Montana and Wyoming. If it needs more than this to stabilize, it may be telling your that it needs attention. That could be worn plugs, dirty throttle body, restricted injectors.
Anything more than about 10 to 30 sceonds is just a waste of fuel.
