Am I screwed?

So, I'm trying a brisket for the first time. It's about 16 lbs. I trimmed and prepped it yesterday, and I set an alarm to but it on the smoker at about 2 a.m.

I slept through the alarms though and didn't get it on until about 5:45.a.m. I had planned to eat for a family function at about 6 p.m.

How screwed am I? I'm cooking at 250, do I dare turn it up?

I'm a brisket virgin -- so any advice would be appreciated.