Your I-20 would not be updated untill its approved by USCIS. Like i said earlier, as long as your visa and I-2- are valid you should be fine. Lets say your visa expires in jan 9 and you are entering US in jan 5-6 by law you have the right to enter the country if you wish to. Once again i'm not an expert in this matter so please cosult your international advisor.

Good luck,

YekloYatri