L1 renewal/ extension from mexico

Hi,

I have L1-B visa valid till Apr 12 2014. I-94 valid till Dec 2015. I can’t apply for L1B extension within USA at USCIS as the risk of denial is high for this case. So planning to go to to Mexico sometime in Feb 2014 for renewal of my L1-B stamp. I have following questions.

In case if the L1-B gets rejected then :

  1. Can I still reenter US with current L1-B visa and I-94?

  2. If allowed how long can I stay legally in USA? Till Apr 12 2014?

Thanks,

Jai