You should be fine, but as mercator stated, mountain weather can be very unpredictable. Just be prepared for cool/cold nights if you are camping (especially around LL) and pack full-fingered gloves. Maybe even a neck tube. I find that after sweating up a climb, the descents can be downright frigid. And I hate being cold.

On my Vancouver-Calgary-Vancouver trip in 2006, I climbed and descended many passes/summits - and the westerly side of Sinclair Pass was by far the most fun. I'm envious.