OPT Extension Denied; H1b cap-exempt pending

My OPT period was valid till Oct 10, 2017 and I filed my OPT extension application on Sep 25, 2017. I changed my employers on Nov 1,2017 and sent an updated I-765 to USCIS. At the same time, my new employer filed an cap exempt H1-b petition in premium processing on Nov 28, 2017 and got the receipt notice. I got an email update today (Dec 4, 2017) stating my OPT extension has been denied.

  1. I understand that I need to stop working, but can I at least work till I get the rejected notice by post.

  2. Also do I have leave the country if I do not get a decision on my H1-b petition before the end of 60 day grace period (Dec 10, 2017)

  3. If my H1-b petition also gets rejected what options do I have. My spouse has H1-b visa. Can I file a I-539 and transfer to H-4 or do I need to leave the country since USCIS would receive the application after 60 day grace period.