Congratulations on your new job! It sounds like much more family-friendly hours.
I've been laid off with no notice, so I'm not especially loyal to employers. They don't care about you, so why knock yourself out for them? (not to be cynical, but I've been so screwed by misplaced loyalty in the past - don't forget that only you have your own best interests in mind.) On the other hand, you never know when your former boss may be your new boss again.
And if you don't show up, that probably means one of your co-workers will have to go in for you, which screws up their holiday shopping plans and family time. So for that reason alone, I'd probably finish out the two weeks with thankfulness that it was the last time!
Good luck in your new job.