You are welcome, Dave.
I view myself a bit on the wimpy side when it comes to cold -- although not the wimpiest. For me, I would leave the capilene top/bottom at home as well. Thinking about it, your MB 30F should be fine if evening lows are at expected level. And then, your base layer, your MontBell down jacket, and your shell jacket should offer plenty of insurance. YMMV, of course.
BTW, I will be hoofing it up there with Brian Green (fellow BPL forum poster) as well -- but taking the Portal route up to Trail Camp and summit:
8/27 - Portal - car camping to get aclimated
8/28 - Trail Camp (12k)
8/29 - summit and back down to Trail Camp
8/30 - back to Portal
Maybe we will bump into each other?